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8-port Gigabit Ethernet Switch User’s Guide

Internet Group Management Protocol (IGMP)

Computers and network devices that want to receive multicast transmissions need to inform nearby routers that they will

become members of a multicast group. The Internet Group Management Protocol (IGMP) is used to communicate this

information. IGMP is also used to periodically check the multicast group for members that are no longer active.

In the case where there is more than one multicast router on a subnetwork, one router is elected as the ‘querier’. This

router then keeps track of the membership of the multicast groups that have active members. The information received

from IGMP is then used to determine if multicast packets should be forwarded to a given subnetwork or not. The router can

check, using IGMP, to see if there is at least one member of a multicast group on a given subnetwork. If there are no

members on a subnetwork, packets will not be forwarded to that subnetwork.

IGMP Versions 1 and 2

Multicast groups allow members to join or leave at any time. IGMP provides the method for members and multicast

routers to communicate when joining or leaving a multicast group.

IGMP version 1 is defined in RFC 1112. It has a fixed packet size and no optional data.

The format of an IGMP packet is shown below:

Figure 5-15. IGMP Message Format

The IGMP Type codes are shown below:

Type Meaning

0x11

Membership Query (if Group Address is 0.0.0.0)

0x11 Specific Group Membership Query (if Group Address is

Present)

0x16 Membership Report (version 2)

0x17 Leave a Group (version 2)

0x12 Membership Report (version 1)

Table 5-11. IGMP Type Codes

IGMP packets enable multicast routers to keep track of the membership of multicast groups, on their respective

subnetworks. The following outlines what is communicated between a multicast router and a multicast group member

using IGMP.

•

A host sends an IGMP “report” to join a group

•

A host will never send a report when it wants to leave a group (for version 1).

•

A host will send a “leave” report when it wants to leave a group (for version 2).

•

Multicast routers send IGMP queries (to the all-hosts group address: 224.0.0.1) periodically to see whether any

group members exist on their subnetworks. If there is no response from a particular group, the router assumes

that there are no group members on the network.

The Time-to-Live (TTL) field of query messages is set to 1 so that the queries will not be forwarded to other subnetworks.

IGMP version 2 introduces some enhancements such as a method to elect a multicast querier for each LAN, an explicit

leave message, and query messages that are specific to a given group.

Summary of Contents for DGS-3308 Series

Page 1: ...DGS 3308 Series 8 Port Gigabit Layer 3 Switch User s Guide First Edition December 2001 651FG3308015 Printed In Taiwan RECYCLABLE ...

Page 2: ...ollten Sie es vom Stromnetz trennen Somit wird im Falle einer Überspannung eine Beschädigung vermieden 13 Durch die Lüftungsöffnungen dürfen niemals Gegenstände oder Flüssigkeiten in das Gerät gelangen Dies könnte einen Brand bzw Elektrischen Schlag auslösen 14 Öffnen Sie niemals das Gerät Das Gerät darf aus Gründen der elektrischen Sicherheit nur von authorisiertem Servicepersonal geöffnet werden...

Page 3: ...ing a D Link office within the applicable warranty period and requesting a Return Material Authorization RMA number If a Registration Card for the product in question has not been returned to D Link then a proof of purchase such as a copy of the dated purchase invoice must be provided If Purchaser s circumstances require special handling of warranty correction then at the time of requesting RMA nu...

Page 4: ...obligation to provide compatibility when there is fault in the third party hardware or software D Link makes no warranty that operation of its software products will be uninterrupted or absolutely error free and no warranty that all defects in the software product within or without the scope of D Link s applicable product documentation will be corrected ...

Page 5: ...ink offices is provided in the back of this manual Trademarks Copyright 2001 D Link Corporation Contents subject to change without prior notice D Link is a registered trademark of D Link Corporation D Link Systems Inc All other trademarks belong to their respective proprietors Copyright Statement No part of this publication may be reproduced in any form or by any means or used to make any derivati...

Page 6: ... radiate radio frequency energy and if not installed and used in accordance with this user s guide may cause harmful interference to radio communications Operation of this equipment in a residential area is likely to cause harmful interference in which case the user will be required to correct the interference at his own expense CE Mark Warning This is a Class A product In a domestic environment t...

Page 7: ...lation 7 Desktop or Shelf Installation 7 Rack Installation 8 Power on 9 Power Failure 9 Identifying External Components 10 Front Panel 10 Rear Panel 10 Side Panels 11 LED Indicators 11 Connecting The Switch 12 PC to Switch 12 Switch to Switch other devices 12 Switch Management and Operating Concepts 14 Local Console Management 14 IP Addresses and SNMP Community Names 15 Traps 16 MIBs 17 SNMP 17 Pa...

Page 8: ...h Information 66 IP Setup 67 Remote Management Setup 69 Configure Ports 70 Serial Port Settings 71 Switch Operation Mode 72 Changing the Switch Operation Mode 73 Layer 2 Switch Settings 76 Layer 3 Switch Mode Setup RIP 77 Advanced Setup 79 Configuring VLANs 79 VLANs by Switch Operating Mode Layer 2 Only and IP Routing 79 Setting Up IP Interfaces 86 Multicasting 89 Layer 2 Multicast Setup 89 IGMP S...

Page 9: ...orwarding Table 136 IGMP Group Table 137 DVMRP Routing Table 138 Reboot and Factory Reset 139 Web Based Network Management 142 Introduction 142 Before You Start 142 General Deployment Strategy 142 VLAN Layout 143 Assigning IP Network Addresses and Subnet Masks to VLANs 143 Defining Static Routes 143 Getting Started 144 Configuring the Switch 144 User Accounts Management 144 Saving Changes 146 Fact...

Page 10: ... TFTP Server 207 Save Changes 207 Factory Reset 208 Restart System 209 Technical Specifications 210 RJ 45 Pin Specification 213 Runtime Switching Software Default Settings 214 Understanding and Troubleshooting the Spanning Tree Protocol 215 Blocking State 215 Listening State 216 Learning State 217 Forwarding State 217 Disabled State 218 Troubleshooting STP 219 Spanning Tree Protocol Failure 219 Fu...

Page 11: ...the Switch to your Ethernet network Chapter 5 Switch Management and Operating Concepts Talks about Local Console Management via the RS 232 DCE console port and other aspects about how to manage the Switch Chapter 6 Using the Console Interface Tells how to use the built in console interface to change set and monitor Switch performance and security Chapter 7 Web Based Network Management Tells how to...

Page 12: ...ional router and its associated WAN interface would then handle routing between the intranetwork and the WAN the Internet for example while the Layer 3 switch would handle routing within the LAN between the Fast Ethernet Layer 2 domains Any installed Layer 2 switches and indeed the entire subnetting scheme would remain in place The DGS 3308FG can also replace key traditional routers for data cente...

Page 13: ...ny optional information Updates forwarding statistics in the Management Information Base Applies security controls A Layer 3 switch can be placed anywhere within a network core or backbone easily and cost effectively replacing the traditional collapsed backbone router The DGS 3308 Layer 3 switch communicates with a WAN router using a standard Gigabit Ethernet or GBIC based port Multiple DGS 3308 s...

Page 14: ...rt for Gigabit Ethernet ports 802 1D Spanning Tree support 802 1Q Tagged VLAN support including GVRP GARP VLAN Registration Protocol support for automatic VLAN configuration distribution 802 1p priority support 4 priority queues Support IGMP Snooping Layer 3 Switching Features Wire speed IP forwarding Hardware based Layer 3 IP switching IP packet forwarding rate up to 12 Mpps 2K active IP address ...

Page 15: ... v 1 Agent Telnet remote control console In band control and configuration via SNMP based software Flash memory for software upgrades This can be done in band via TFTP Built in SNMP management RFC 1213 MIB II RFC 1493 Bridge MIB RFC 1757 Four groups of RMON Statistics History Alarm and Event RFC 1724 RIP v2 MIB RFC 2737 Entity MIB RFC 2674 P Bridge MIB RFC 2233 IF MIB RFC 2096 IP Forward MIB RFC 1...

Page 16: ...with Collision Detection CSMA CD Ethernet protocol Gigabit Ethernet Technology Gigabit Ethernet is an extension of IEEE 802 3 Ethernet utilizing the same packet structure format and support for CSMA CD protocol full duplex flow control and management objects but with a tenfold increase in theoretical throughput over 100Mbps Fast Ethernet and a one hundred fold increase over 10Mbps Ethernet Since i...

Page 17: ...ntact your local D Link reseller for replacement Installation Use the following guidelines when choosing a place to install the Switch The surface must support at least 3 kg The power outlet should be within 1 82 meters 6 feet of the device Visually inspect the power cord and see that it is secured to the AC power connector Make sure that there is proper heat dissipation from and adequate ventilat...

Page 18: ...IA standard sized 19 inch rack which can be placed in a wiring closet with other equipment To install attach the mounting brackets on the Switch s side panels one on each side and secure them with the screws provided Figure 2 2A Attaching the mounting brackets to the Switch Then use the screws provided with the equipment rack to mount the switch on the rack ...

Page 19: ... should respond as follows All LED indicators will momentarily blink This blinking of the LED indicators represents a reset of the system The Power LED indicator will blink while the Switch loads onboard software and performs a self test After approximately 20 seconds the LED will light again to indicate the switch is in a ready state The Console LED indicator will remain ON if there is a connecti...

Page 20: ...he DGS 3308FG Figure 3 1b Front panel view of the DGS 3308TG Comprehensive LED indicators display the status of the Switch and the network see the LED Indicators section below An RS 232 DCE console port for setting up and managing the switch via a connection to a console terminal or PC using a terminal emulation program Six Gigabit Ethernet ports 1000BASE SX for DGS 3308FG and 1000BASE T for DGS 3...

Page 21: ...rculation system components might overheat which could lead to system failure LED Indicators The LED indicators of the Switch include Power Console Link Act and RPS In Use The following shows the LED indicators for the Switch along with an explanation of each indicator Power This indicator on the front panel should be lit during the Power On Self Test POST Itwill light green approximately 2 second...

Page 22: ...igure 4 1 Switch connected to a PC or Workstation The LED indicators for PC connection are dependent on the LAN card capabilities If LED indicators are not illuminated after making a proper connection check the PC s LAN card the cable Switch conditions and connections The following LED indicator state is possible for a PC to Switch connection The Link Act LED indicator lights up upon hooking up a ...

Page 23: ...8 port Gigabit Ethernet Switch User s Guide 13 Figure 4 2 Switch to switch connection ...

Page 24: ...h even if the network is down Local console management uses the terminal connection to operate the console program built in to the Switch see Chapter 6 Using the Console Interface A network administrator can manage control and monitor the switch from the console program The DGS 3308 contains a CPU memory for data storage flash memory for configuration data operational programs and SNMP agent firmw...

Page 25: ... Each Switch must be assigned its own IP Address which is used for communication with an SNMP network manager or other TCP IP application for example BOOTP TFTP The Switch s default IP address is 10 90 90 90 You can change the default Switch IP Address to meet the specification of your networking address scheme The Switch is also assigned a unique MAC address by the factory This MAC address cannot...

Page 26: ...as serious as a reboot someone accidentally turned OFF the Switch or less serious like a port status change The Switch generates traps and sends them to the network manager trap recipient Trap recipients are special users of the network who are given certain rights and access in overseeing the maintenance of the network Trap recipients will receive traps sent from the Switch they must immediately ...

Page 27: ...on to the standard MIB II the Switch also supports its own proprietary enterprise MIB as an extended Management Information Base These MIBs may also be retrieved by specifying the MIB s Object Identity OID at the network manager MIB values can be either read only or read write Read only MIBs variables can be either constants that are programmed into the Switch or variables that change while the Sw...

Page 28: ...ng aging time can result in dynamic forwarding table entries that are out of date or no longer exist This may cause incorrect packet forwarding decisions by the Switch If the Aging Time is too short however many entries may be aged out too soon This will result in a high percentage of received packets whose source addresses cannot be found in the forwarding table in which case the switch will broa...

Page 29: ...n IP Interface another name for subnet Network Address the resulting 32 bit number from a bitwise logical AND operation performed between an IP address and a subnet mask Subnet Address another name for network address Note In a subnetted network all addresses consist of two parts an IP address and a subnet mask The two are used together and one is meaningless without the other IP Addresses The Int...

Page 30: ...kes the task of dividing a network into subnetsa bit easier There are 5 address classes The first 4 bits in the IP address determine which class the IP address falls in Class A addresses begin with 0xxx or 1 to 126 decimal Class B addresses begin with 10xx or 128 to 191 decimal Class C addresses begin with 110x or 192 to 223 decimal Class D addresses begin with 1110 or 224 to 239 decimal Class E a...

Page 31: ...t address cannot be all 0 s or all 1 s A 1 bit subnet mask is also not allowed Calculating the Number of Subnets and Nodes To calculate the number of subnets and nodes use the formula 2n 2 where n the number of bits in either the subnet mask or the node portion of the IP address Multiplying the number of subnets by the number of nodes available per subnet gives the total number of nodes for the en...

Page 32: ... 0 17 510 32766 16710660 10 255 255 192 0 18 1022 16382 16742404 11 255 255 224 0 19 2046 8190 16756740 12 255 255 240 0 20 4094 4094 16760836 13 255 255 248 0 21 8190 2046 16756740 14 255 255 252 0 22 16382 1022 16742404 15 255 255 254 0 23 32766 510 16710660 16 255 255 255 0 24 65534 254 16645636 17 255 255 255 128 25 131070 126 16514820 18 255 255 255 192 26 262142 62 16252804 19 255 255 255 22...

Page 33: ... mode is to assign all ports to a single 802 1Q VLAN named DEFAULT_VLAN As new VLANs are created the member ports assigned to the new VLAN will be removed from the DEFAULT_ VLAN port member list 4 The DEFAULT_VLAN has a VID 1 An IP interface called System in the IP interface entry menu also has a VID 1 and therefore corresponds to the DEFAULT_VLAN 5 There is no difference in the creation deletion ...

Page 34: ... configured as either tagging or untagging The untagging feature of IEEE 802 1Q VLANs allow VLANs to work with legacy switches that don t recognize VLAN tags in packet headers The tagging feature allows VLANs to span multiple 802 1Q compliant switches through a single physical connection and allows Spanning Tree to be enabled on all ports and work normally The IEEE 802 1Q standard restricts the fo...

Page 35: ...IEEE 802 1Q 802 1p tag The tag is contained in the following two octets and consists of 3 bits or user priority 1 bit of Canonical Format Identifier CFI used for encapsulating Token Ring packets so they can be carried across Ethernet backbones and 12 bits of VLAN ID VID The 3 bits of user priority are used by 802 1p The VID is the VLAN identifier and is used by the 802 1Q standard The tag is inser...

Page 36: ...h will drop the packet Because of the existence of the PVID for untagged packets and the VID for tagged packets tag aware and tag unaware network devices can coexist on the same network A switch port can have only one PVID but can have as many VIDs as the switch has memory in its VLAN table to store them Because some devices on a network may be tag unaware a decision must be made at each port on a...

Page 37: ...02 1Q VLAN that exists on the switch Even though a switch inspects a packet s IP address to determine VLAN membership no route calculation is performed the RIP or OSPF protocols are not employed and packets traversing the switch are bridged using the Spanning Tree algorithm A switch that implements layer 3 or subnet VLANs without performing any routing function between these VLANs is referred to a...

Page 38: ...tem default 1 10 32 0 0 10 32 0 1 Engineering 2 10 64 0 0 10 64 0 1 Marketing 3 10 96 0 0 10 96 0 1 Finance 4 10 128 0 0 10 128 0 1 Sales 5 10 160 0 0 10 160 0 1 Backbone 6 10 192 0 0 10 192 0 1 Table 5 6 VLAN Example Assigned IP Interfaces The 6 IP interfaces each with an IP address listed in the table above and a subnet mask of 255 224 0 0 can be entered into the Setup IP Interface menu Spanning...

Page 39: ...rom any combination of ports contained within a single switch in user specified groups Automatically reconfigures the spanning tree to compensate for the failure addition or removal of any element in the tree Reconfigures the spanning tree without operator intervention STP Operation Levels The Switch allows for two levels of operation the switch level and the port level The switch level forms a sp...

Page 40: ...Port Priority A relative priority for each port lower numbers give a higher priority and a greater chance of a given port being elected as the root port 32768 Port Cost A value used by STP to evaluate paths STP calculates path costs and selects the path with the minimum cost as the active path 19 100Mbps Fast Ethernet ports 4 1000Mbps Gigabit Ethernet ports Table 5 8 STP Parameters Port Group Leve...

Page 41: ... might not be ideal For instance connecting higher speed links to a port that has a higher number than the current root port can cause a root port change STP Port States The BPDUs take some time to pass through a network This propagation delay can result in topology changes where a port that transitioned directly from a Blocking state to a Forwarding state could create temporary data loops Ports m...

Page 42: ...k goes through the blocking state and then transitions through the states of listening and learning at power up If properly configured each port stabilizes to the forwarding or blocking state No packets except BPDUs are forwarded from or received by STP enabled ports until the forwarding state is enabled for that port Default Spanning Tree Configuration Feature Default Value Enable state STP enabl...

Page 43: ...wing formulas when setting the above parameters Max Age 2 x Forward Delay 1 second Max Age 2 x Hello Time 1 second Port Priority A Port Priority can be from 0 to 255 The lower the number the greater the probability the port will be chosen as the Root Port Port Cost A Port Cost can be set from 1 to 65535 The lower the number the greater the probability the port will be chosen to forward packets Ill...

Page 44: ...ed to one optional Gigabit port on both switch B and C The redundant link between switch B and C is deliberately chosen as a 100 Mbps Fast Ethernet link default port cost 19 Gigabit ports could be used but the port cost should be increased from the default to ensure that the link between switch B and switch C is the blocked link Internet Protocols This is a brief introduction to TCP IP or the coll...

Page 45: ...cally important Hardware and software designers are free to improve the performance or to reduce the cost of accomplishing the task of each protocol layer so long as the data format between layers conforms to the defined formats and of course the layer s task is accomplished The protocol layer concept currently used by the Internet the OSI seven layer model was developed from earlier simpler layer...

Page 46: ...ce is part of the operating system and is usually not published and therefore not well known In addition internal protocol stack interfaces are generally proprietary This means that communication within the protocol stack has the same characteristics as a protocol in that two protocol stacks from the same operating system vendor will communicate within the stack in the same way The difference from...

Page 47: ...work devices to direct data to destinations in other networks IP also allows for transmitting packets from a single point to multiple destinations known as IP multicasting Layer 4 This is commonly called the transport layer It is responsible for the communication path between user applications and the network The Transmission Control Protocol TCP and the User Datagram Protocol UDP are the most wel...

Page 48: ... and the data in the previous header is used to forward the packet This process is called encapsulation To send a packet over the internet many levels of encapsulation may be used and IP does all of this transparently to the user TCP and UDP Well Known Ports Network devices and computers connected to a network can have multiple connections with other devices and computers simultaneously Received p...

Page 49: ...applications that do not need sequences of packets to be put together UDP also does not keep track of what is sent and cannot resend data UDP does use port numbers in much the same way as TCP UDP allows several programs to make connections to a server at the same time UDP port numbers are used just like TCP port numbers and there are well known port numbers for servers that use UDP Figure 5 10 UDP...

Page 50: ...ket is sent If the sender does not receive an acknowledgement within a reasonable amount of time the data is resent The window field controls the amount of data in transit at any one time Each end of a connection indicates how much data it is currently able to receive by putting that number of octets in the window field As the computer receives data the number in the window field is decremented an...

Page 51: ...it by the manufacturer An Ethernet header is a 14 octets and includes the source and destination MAC addresses and a type code For a computer or network device to have an IP address a database must exist somewhere on the network to keep track of which MAC address corresponds to which IP address The type code is used to specify one of several protocol families that may be in use on the network A ch...

Page 52: ...ame Each client must be able to contact at least one DNS server and each DNS server must be able to contact at least one root DNS server The IP address of a local DNS server is often supplied by a DHCP or BOOTP server DHCP Servers The Dynamic Host Configuration Protocol DHCP is used to dynamically assign a TCP IP network configuration to network devices and computers on the network It also ensures...

Page 53: ...s is written to the packet s destination field and the packet is sent If the destination IP address does not have an entry in the local ARP cache an ARP request must be sent to resolve the IP address into a MAC address The packet must wait for a response from the destination before being sent ARP requests that are received from the network have their IP and MAC address pair extracted The local ARP...

Page 54: ...rs 224 0 0 5 OSPF IGP Routers 224 0 0 6 OSPF IGP Designated Routers 224 0 0 7 ST Routers 224 0 0 8 ST Hosts 224 0 0 9 All RIP2 Routers 224 0 0 10 All IGRP Routers 224 0 0 11 Mobile Agents 224 0 0 12 DHCP Servers and Relay Agents 224 0 0 13 All PIM Routers 224 0 0 14 RSVP Encapsulation 224 0 0 15 All CBT Routers 224 0 0 16 Designated Sbm 224 0 0 17 All Sbms 224 0 0 18 VRRP 224 0 0 19 through 224 0 ...

Page 55: ... has a fixed packet size and no optional data The format of an IGMP packet is shown below Figure 5 15 IGMP Message Format The IGMP Type codes are shown below Type Meaning 0x11 Membership Query if Group Address is 0 0 0 0 0x11 Specific Group Membership Query if Group Address is Present 0x16 Membership Report version 2 0x17 Leave a Group version 2 0x12 Membership Report version 1 Table 5 11 IGMP Typ...

Page 56: ...et was received on Otherwise the router drops the packet This way all routers on a network will receive at least on copy of the packet Flooding generates a large number of duplicated packets and wastes network bandwidth It also requires multicast routers to keep an entry in their table of recently received multicast packets wasting some the router s memory Multicast Spanning Trees Spanning Trees a...

Page 57: ...ion trees Reverse Path Multicasting RPM The RPM algorithm is an enhancement of the RPB and TRPB algorithms RPM constructs delivery trees that span only subnetworks with group members or subnetworks along the shortest path to routers attached to subnetworks that have group members The RPM tree is then pruned so that multicast packets are forwarded only along paths that lead to group members The fir...

Page 58: ...he Protocol Independent Multicast Dense Mode PIM DM routing protocol also uses the RPM algorithm for constructing distribution trees but PIM DM requires the presence of a unicast routing protocol for finding routes back to the multicast source PIM DM is however independent of the mechanisms used by the unicast routing protocol It floods multicast messages until it receives prune messages and also ...

Page 59: ...route depended on the route that just disappeared Thus negative information does not always propagate quickly Another technique used to solve the slow convergence problem employs hold down Hold down forces a participating router to ignore information about a network for a fixed period of time following the receipt of a message that claims a network is unreachable Typically the hold down period is ...

Page 60: ... optional list of network and distance pairs The message format used by version 1 is shown below Figure 5 17 RIP v 1 Message Format The COMMAND field specifies an operation according the following table Command Meaning 1 Request for partial or full routing information 2 Response containing network distance pairs from sender s routing table 3 Turn on trace mode obsolete 4 Turn off trace mode obsole...

Page 61: ...retation and Aggregation Because RIP was originally designed to be used with classful addresses version 1 did not include any provision for a subnet mask When subnet addressing was added to IP version 1 of RIP was extended to permit routers to exchange subnetted addresses However because RIP 1 update messages do not contain explicit mask information an important restriction was added a router can ...

Page 62: ...o not contain an explicit length field or an explicit count of entries Instead RIP assumes that the underlying delivery mechanism will tell the receiver the length of an incoming message In particular when used with TCP IP RIP messages rely on UDP to tell the receiver the message length RIP operates on UDP port 520 Although a RIP request can originate at other UDP ports the destination UDP port fo...

Page 63: ...e additional LANs the maximum span only increases to 4 Similarly extending the hierarchy one more level only increases the span to 6 Thus the limit that RIP imposes affects large autonomous systems or autonomous systems that do not have a hierarchical organization Even in the best cases however hop counts provide only a crude measure of network capacity or responsiveness Thus using hop counts does...

Page 64: ...re You Start The DGS 3308 Layer 3 Switch supports a wide array of functions and gives great flexibility and increased network performance by eliminating the routing bottleneck between the WAN or Internet and the Intranet Its function in a network can be thought of as a new generation of router that performs routing functions in hardware rather than software It is a router that also has up to 8 ind...

Page 65: ...ayer 3 VLAN consisting of 4 ports could be connected to 4 layer 2 switches If these layer 2 switches each have 8 ports then the Layer 3 VLAN would contain 4 x 8 32 end nodes Assigning an IP subnet to the Layer 3 VLAN would allow wire speed IP routing from the WAN to each end node and between end nodes So the IP subnets for a network must be determined first and the VLANs configured on the switch t...

Page 66: ...yping in a new value You can use the backspace and delete keys to erase characters behind and in front of the cursor 3 The up and down arrow keys the left and right arrow keys the tab key and the backspace key can be used to move between selected items 4 Items in UPPERCASE are commands Moving the selection to a command and pressing Enter will execute that command e g APPLY etc Please note that the...

Page 67: ...nd password fields blank Note The Switch s operational mode Layer 3 or Layer 2 is displayed in the upper right hand corner of every menu in the console The switch operational mode is changed under Switch Settings from the Main Menu and is described later in this manual Press Enter in both the username and password fields You will be given access to the main menu shown below ...

Page 68: ...ain Menu Note The first user automatically gets Root privileges See Table 6 1 It is recommended to create at least one Root level user for the Switch Setup User Accounts To create a new user account highlightSetup User Accounts from the Main Menu and pressEnter ...

Page 69: ...ernet Switch User s Guide 59 Figure 6 3 Main Menu Figure 6 4 Setup User Accounts screen User Accounts Management From the Main Menu highlight Setup User Accounts and press Enter then the Setup User Accounts menu appears ...

Page 70: ... There are three levels of user privileges Root and User and User Some menu selections available to users with Root privileges may not be available to those with User and User privileges The following table summarizes the Root User and User privileges Switch Configuration Privilege Management Root User User Configuration Yes Read Only Read Only Network Monitoring Yes Read Only Read Only Community ...

Page 71: ...in RAM and reloads the stored settings from the NV RAM Thus it is necessary to save all setting changes to NV RAM before rebooting the Switch To retain any configuration changes permanently highlight Save Changes from the Main Menu The following screen will appear to verify that your new settings have been saved to NV RAM Figure 6 5 Main Menu Figure 6 6 Save Changes screen ...

Page 72: ...ored in NV RAM is to save a new configuration using Save Changes from the Main Menu or to execute a factory reset from the System Reboot menu click Reboot on the Main Menu This will clear all settings and restore them to their initial values listed in the Appendix These are the configuration settings entered at the factory and are the same settings present when the Switch was purchased Figure 6 7 ...

Page 73: ...e erased and the Switch will return to the state it was in when it was purchased Logging Onto The Switch Console To log inonce you have created a registered user from the login screen 1 Type in your username and pressEnter 2 Type in your password and pressEnter 3 The Main Menu screen will be displayed based on your access level or privilege Updating or Deleting User Accounts To update or delete a ...

Page 74: ...cess Level Root field until the appropriate level is displayed Root User or User 6 Highlight APPLY and pressEnter to make the change effective 7 You must enter the configuration changes into the non volatile ram NV RAM using Save Changes from the Main Menu if you want the configuration to be used after a switch reboot Only a user with Root privileges can make changes to user accounts Viewing Curre...

Page 75: ...light APPLY and pressEnter to make the deletion of the selected user take effect 4 You must enter the configuration changes into the non volatile RAM NV RAM using Save Changes from the Main Menu if you want the configuration to be used after a switch reboot Only users with Root privileges can delete user accounts Setting Up The Switch Basic Setup This section will help prepare the Switch user by d...

Page 76: ...ROM and Firmware updates and to obtain the Switch s MAC address for entry into another network device s address table if necessary You can also enter the name of the System its location and the name and telephone number of the System Administrator It is recommended that the person responsible for the maintenance of the network system that this Layer 3 switch is installed on be listed here Power Su...

Page 77: ...System such as SNMP v1 or to be able to access the Switch using the Telnet protocol or the Web based Manager Please see the next chapter for Web based network management information The IP Setup menu lets you specify how the Switch will be assigned an IP address to allow it to be identified on the network To setup the Switch for remote management Highlight IP Setup from the Main Menu The following...

Page 78: ...m options are BOOTP The Switch will send out a BOOTP broadcast request when it is powered up The BOOTP protocol allows IP addresses network masks and default gateways to be assigned by a central BOOTP server If this option is set the Switch will first look for a BOOTP server to provide it with this information before using the default or previously entered settings DHCP The Switch will send out a ...

Page 79: ...his field unchanged Management VID Allows the input of a VLAN VID to restrict access to the management module on the Switch to a single VLAN Remote Management Setup This allows the Switch to send traps messages about errors etc to management stations on the network Highlight Remote Management Setup on the Main Menu and press Enter The trap recipients can be setup from the following screen Figure 6...

Page 80: ...8 port Gigabit Ethernet Switch User s Guide 70 Setup Trap Recipients Figure 6 15 Setup Trap Recipients screen Configure Ports Highlight Configure Ports from the Main Menu and pressEnter ...

Page 81: ...plex state of the port There are two choices Auto and 1000M Full Auto allows the port to automatically determine the fastest settings the device the port is connected to can handle and then to use those settings There is no automatic adjustment of port settings with any option other than Auto Serial Port Settings The Serial Port Settings screen allows the configuration of the Switch s serial port ...

Page 82: ...elnet sessions in this field Switch Operation Mode Note The Switch will retain the configuration entered for IP Routing when in Layer 2 Only mode if the configuration is saved to NV RAM but the IP Routing configuration will not be active The IP Routing configuration will become active when the Switch is again put in IP Routing mode Note Putting the Switch in IP Routing mode does not by itself enab...

Page 83: ...ddresses as in Layer 2 above 802 1Q VLANs are supported and the Switch is considered as a VLAN tag aware device The Switch must be rebooted when changing the operation mode before the new operation mode can take effect Changing the Switch Operation Mode To change the Switch s operating mode Highlight Switch Settings on the Main Menu and pressEnter Figure 6 18 Switch Settings screen Highlight Switc...

Page 84: ...eration modes Layer 2 Only Support IEEE 802 1Q VLANs and IP Routing Support IEEE 802 1Q VLANs To make a change in the operation mode of the Switch effective highlightAPPLY and pressEnter Figure 6 20 Change Mode Confirmation screen Type y and press Enter The Switch will then save the changes made during the current session and reboot The Switch must be rebooted to change the operation mode ...

Page 85: ...er s Guide 75 Switch Settings IP Routing Mode Once the Switch is configured for IP Routing Layer 3 Switching and rebooted the Main Menu adds some functions compared to the Layer 2 Only mode Figure 6 21 Main Menu Layer 3 IP Routing Mode ...

Page 86: ...ng Mode Layer 2 Switch Settings Note Layer 2 Switch functions and settings are also available when the Switch is configured to operate in the IP Routing Layer 3 mode To access the Layer 2 Switch Settings menu highlightLayer 2 Switch Settings on the Switch Settings menu and press Enter ...

Page 87: ...e Switch s reaction to a Broadcast Multicast storm Broadcast Storm Mode Disabled This field can be toggled between Enabled and Disabled using the space bar This enables or disables globally the Switch s reaction to Broadcast storms triggered at the threshold set above Multicast Storm Mode Disabled This field can be toggled between Enabled and Disabled using the space bar This enables or disables g...

Page 88: ...ser s Guide 78 Figure 6 24 Setup Layer 3 IP Networking menu Now highlight Setup RIP Configuration from the Setup Layer 3 IP Networking menu above and pressEnter to access the following screen Figure 6 25 Setup RIP Configuration screen ...

Page 89: ... difference in the setup between the two switch operation modes only one section will be presented Configuring VLANs Note The Switch allows the assignment of an IP interface to each VLAN in IP Routing mode The VLANs must be configured before setting up the IP interfaces VLANs in Layer 2 Only Mode The Switch reserves one VLAN VID 1 called the DEFAULT_VLAN for internal use The factory default settin...

Page 90: ...e an 802 1Q VLAN highlightEdit 802 1Q VLANs and press Enter Figure 6 27 Edit 802 1Q VLANs menu To create an 802 1Q VLAN toggle the Action Add Modify field to Add Modify using the space bar Enter a VLAN ID number in the VID field and a name for the new VLAN in the VLAN Name field ...

Page 91: ...as either a Tagged or an Untagged port Highlight the first field of Tagging U T field Each port s state can be set by highlighting the port s entry using the arrow keys and then toggling between U or T using the space bar U specifies the port as an Untagged member of the VLAN When an untagged packet is transmitted by the port the packet header remains unchanged When a tagged packet exits the port ...

Page 92: ... Edit 802 1Q VLANs menu Note The default VLAN includes all of the ports on the Switch at first boot As new VLANs are added the member ports of the new VLAN are deleted from the default VLAN To configure the member ports of an 802 1Q VLAN Figure 6 29 VLAN Menu ...

Page 93: ...associates a port with a specific VLAN and is used to make forwarding decisions for untagged packets received by the port For example if port 2 is assigned a PVID of 3 then all untagged packets received on port 2 will be assigned to VLAN 3 This number is generally the same as the VID number assigned to the port in the Edit 802 1Q VLANs menu above Use the arrow keys to highlight the remaining field...

Page 94: ...VLAN highlightEdit 802 1Q VLANs and press Enter Figure 6 32 Edit 802 1Q VLANs screen To edit an existing 802 1Q VLAN highlight the Action Add Modify field and toggle between Add Modify and Delete In the Add Modify mode both individual entrees to a selected VLAN and entire VLANs can be added In the ...

Page 95: ...ing U T field Each port s state can be set by highlighting the port s entry using the arrow keys and then toggling between U or T using the space bar U specifies the port as an Untagged member of the VLAN When an untagged packet is transmitted by the port the packet header remains unchanged When a tagged packet exits the port the tag is stripped and the packet is changed to an untagged packet T sp...

Page 96: ...ng IP interface An example is presented below VLAN Name VID Switch Ports System default 1 5 Engineering 2 6 7 Marketing 3 8 Finance 4 2 Sales 5 3 Backbone 6 4 Table 5 5 VLAN Example Assigned Ports In this case 6 IP interfaces are required so a CIDR notation of 10 32 0 0 11 or a 11 bit addressing scheme will work This addressing scheme will give a subnet mask of 11111111 11100000 00000000 00000000 ...

Page 97: ...0 0 can be entered into the Setup IP Interface menu Note IP interfaces consist of two parts a subnet mask and an IP address Note Each IP interface listed above will give a maximum of 2 097 150 unique IP addresses per interface assuming the 10 xxx xxx xxx notation To setup IP Interfaces on the switch Highlight Layer 3 IP Networking from the Main Menu and press Enter Figure 6 33 Setup Layer 3 IP Net...

Page 98: ...and Delete using the space bar This enables the addition modification of a new or existing IP interface entry or the deletion of an existing entry Interface Name Allows the entry of a name for the IP interface The default IP interface is named System IP Address The IP address to be assigned to this subnet Subnet Mask The subnetmask to be applied to this subnet It has the same form as an IP address...

Page 99: ...yer 2 Multicast Setup To access the Multicasting Menu highlightMulticasting from the Main Menu and pressEnter Figure 6 35 Multicasting Menu IGMP Snooping Settings by VLAN To Enable or Disable IGMP Snooping for a VLAN highlightIGMP Snooping Settings and press Enter ...

Page 100: ...IP address is smaller than the current V2 Querier the IGMP interface will become the querier for the VLAN When receiving an IGMPv2 leave packet the IGMP interface will issue an IGMPv2 Group Specific Query packet immediately and wait one second to see if any IGMP report is received on the Ethernet port If not the Ethernet port will be removed from the IGMP group member list and the group s multicas...

Page 101: ...the VLAN that will be receiving the multicast packets Enter the MAC address of the multicast source and then enter the member ports Each port can be an Egress Forbidden or a Non member of the multicast group on a per VLAN basis To set a port s multicast group membership status highlight the first field of E F Each port s multicast group membership can be set individually by highlighting the port s...

Page 102: ...lticast messages coming from the network to be propagated to the router The purpose of a router port is to enable UDP multicast packets and IGMP multicast group membership messages to reach multiple ports of a multicast enabled router Routers do not implement IGMP snooping or transmit forward IGMP report packets Thus forwarding all IP UDP multicast packets to a static router port on the DGS 3308 g...

Page 103: ...elong to Highlight the first field of Router Port M Each port can be set individually as a router port by highlighting the port s entry using the arrow keys and then toggling between M and using the space bar Highlight APPLY and press enter to make the changes current Use Save Changes from the Main Menu to enter the changes into NV RAM To delete an entry select Delete and enter the VID of the VLAN...

Page 104: ...er s Guide 94 Figure 6 40 IP Multicast Settings menu Multicast Interface Configuration To configure the multicast interface highlightMulticast Interface Configuration and press Enter Figure 6 41 Multicast Interface Configuration screen ...

Page 105: ...Configuration To configure the IGMP interface highlight IGMP Interface Configuration from the IP Multicasting Settings menu and pressEnter Figure 6 42 IGMP Interface Configuration screen Interface Name Enter the name of the interface in this field This interface must be previously defined Querier State This field can be toggled between V1 Querier and V2 Querier This is the version of IGMP that the...

Page 106: ... allows you to enter a new IGMP Static Member into the table or to modify an existing entry Delete allows you to delete an existing entry Interface Name Enter the IP Interface name the IGMP Static Member belongs to in this field IGMP Static Group Enter the IP address of the IGMP Static Group in this field Group MAC Addr Displays the MAC address corresponding to the IGMP Static Group IP address ent...

Page 107: ... extended for multicast delivery It relies upon RIP hop counts to calculate shortest paths back to the source of a multicast message but defines a route cost to calculate which branches of a multicast delivery tree should be pruned once the delivery tree is established Note When a sender initiates a multicast DVMRP initially assumes that all users on the network will want to receive the multicast ...

Page 108: ...ot pruned if there is an alternative route Probe Interval 10 This field allows an entry between 1 and 65 535 seconds and defines the interval between probes The default is 10 State Disabled Toggle between Enabled and Disabled to enable or disable DVMRP for the IP interface The default is Disabled Include Unknown Neighbor Report Disabled Allows the Layer 3 switch to accept a DVMRP route report from...

Page 109: ...messages indicating that there are no multicast members on their respective branches PIM DM then removes these branches prunes them from the multicast delivery tree Note Because a member of a pruned branch of a multicast delivery tree may want to join a multicast delivery group at some point in the future the protocol periodically removes the prune information from its database and floods multicas...

Page 110: ...hen IGMP query packets RIPv2 multicast DVMRP multicast PIM DM multicast packets are detected flowing into a port The Action field can be toggled between Add Modify and Delete using the space bar To add a port to the static router port table selectAdd Modify and enter the VID of the VLAN the router port will belong to Highlight the first field of Router Port Each port can be set individually as a r...

Page 111: ...Switch User s Guide 101 Mirroring To configure a port for port mirroring highlight Mirroring from the Main Menu and pressEnter Figure 6 47 Mirroring Menu To select the target port highlightTarget Port Selection and pressEnter ...

Page 112: ...ere information will be duplicated and sent for capture and network analysis This is the port where a network analyzer would be attached to capture packets duplicated from the source port To select the source port s for mirroring highlight Port Mirroring Settings and pressEnter Figure 6 49 Port Mirroring Settings screen ...

Page 113: ... slower port because many packets will be dropped Priority To configure a forwarding priority for a given MAC address highlight Priority from the Main Menu and pressEnter Figure 6 50 Setup MAC Address Priority screen Action Toggle between Add Modify and Delete using the space bar VID Enter the VID VLAN ID in this field MAC Address Enter the MAC address for which the priority queue is required this...

Page 114: ...de 104 Filtering Layer 2 Filtering Layer 2 Only switch operation mode To enter a MAC address into the filtering table Highlight Filtering from the Main Menu and pressEnter Figure 6 51 Filtering Menu Highlight MAC Address Filter and press Enter ...

Page 115: ... MAC address The Source Destination field can be toggled between Src source Dst destination and Either Highlight APPLY and press Enter to make the changes current Use Save Changes from the Main Menu to save the changes to NV RAM Layer 3 IP Routing Filtering The Switch is in IP Routing switch operation mode With the Switch configured to Layer 3 Operation mode both MAC and IP addresses can be entere...

Page 116: ...ress into the filtering table highlight MAC Address Filter and pressEnter Figure 6 54 Setup MAC Address Filter screen The Action field can be toggled between Add Modify and Delete using the space bar Enter the VLAN ID in the VID field and the MAC address to be filtered in the MAC Address field ...

Page 117: ...ss into the filtering table highlight IP Address Filter from the Filtering Menu and press Enter Figure 6 55 IP Address Filter screen The Action field can be toggled between Add Modify and Delete using the space bar Enter the IP address to be filtered in the IP Address field The Source Destination field can be toggled between Src source Dst destination and Either The IP address entered into the fil...

Page 118: ...r 2 Forwarding Layer 2 Only switch operation mode To enter a MAC address into the switch s forwarding table highlight Forwarding from the Main Menu and press Enter Figure 6 56 Forwarding Menu Highlight MAC Address Forwarding from the Forwarding Menu and pressEnter ...

Page 119: ...e the changes current Use Save Changes from the Main Menu to enter the changes into NV RAM IP Routing Forwarding IP routing Switch Operation Mode With the Switch in Layer 3 Operation mode entrees into the Switch s forwarding table can be made using both MAC addresses and IP addresses Static IP forwarding is accomplished by the entry of a Static IP Route Static Address Resolution Protocol ARP entre...

Page 120: ...g and pressEnter Figure 6 59 MAC Address Forwarding screen The Action field can be toggled between Add Modify and Delete using the space bar Enter the VLAN ID in the VID field and the MAC address to be statically entered in the forwarding table in the MAC Address field Enter the port number in the Port field ...

Page 121: ...r Enter the IP address in the IP Address field and subnet mask in the Subnet Mask field The IP address of the gateway usually a router with a connection to a WAN or the Internet is entered in the Gateway IP field and a corresponding metric a number representing the distance the gateway is from the IP interface in hops or the number or routers between the IP interface and the gateway is entered in ...

Page 122: ...rface name in the Interface field the corresponding IP address in the IP Address field and the MAC address in the last field Highlight APPLY and press Enter to make the changes current Use Save Changes from the Main Menu to enter the changes into NV RAM Spanning Tree Switch Spanning Tree Settings To globally configure STP on the Switch highlight Spanning Tree on the Main Menu and pressEnter ...

Page 123: ...ello Time The Hello Time can be set from 1 to 10 seconds This is the interval between two transmissions of BPDU packets sent by the Root Bridge to tell all other Switches that it is indeed the Root Bridge If you set a Hello Time for your Switch and it is not the Root Bridge the set Hello Time will be used if and when your Switch becomes the Root Bridge Note The Hello Time cannot be longer than the...

Page 124: ...r the group Redundant links will be blocked just as redundant links are blocked on the switch level Note The STP on the switch level blocks redundant links between switches and similar network devices The port level STP will block redundant links within an STP Group Note It is advisable to define an STP Group to correspond to a VLAN group of ports To define which ports will be members of an STP Gr...

Page 125: ...ngle link s bandwidth Trunking also known as link aggregation is most commonly used to link a bandwidth intensive network device or devices such as a server or server farm to the backbone of a network Note The DGS 3308 allows the creation of up to 4 port trunk groups each consisting of up to 4 links ports The aggregated links must be contiguous they must have sequential port numbers and all of the...

Page 126: ...een Enter the group ID of one of the six possible port trunk groups configurable on the switch in the Group ID 1 field Enter the desired port number in the second field and specify the Group Width 2 This is the number of ports in sequential order from the base port that will be included in the port trunk group The Method Disabled field can be toggled between TRUNK and Disabled and is used to turn ...

Page 127: ...ices allow the switch firmware to be upgraded by transferring a new firmware file from a TFTP server to the switch A configuration file can also be loaded into the switch from a TFTP server switch settings can be saved to the TFTP server and a history log can be uploaded from the switch to the TFTP server Upgrade Firmware from TFTP Server To update the Switch s firmware h ighlight Upgrade Firmware...

Page 128: ...o perform the file transfer TFTP server software is a part of many network management software packages or can be obtained as a separate program Highlight APPLY and press Enter record the IP address of the TFTP server Use Save Changes from the Main Menu to enter the address into NV RAM Highlight START and press Enter to initiate the file transfer Download Configuration File from TFTP Server To dow...

Page 129: ...h configuration file on the server Highlight APPLY and press Enter record the IP address of the server Use Save Changes from the Main Menu to enter the address into NV RAM Highlight START and press Enter to initiate the file transfer Upload Configuration File to TFTP Server To upload a settings file to the TFTP server highlight Upload Configuration File to TFTP Server and press Enter ...

Page 130: ...n File to TFTP Server screen Enter the IP address of the server and the path and filename of the settingsfile on the server and pressAPPLY Save Log to TFTP Server To save a history log to a TFTP server highlight Save Log to TFTP Server on the Switch Utilities menu and press Enter ...

Page 131: ...een Enter the IP address of the server and the path and filename for the history log on the server HighlightAPPLY and press Enter to make the changes current Ping To test the connection with another network device using Ping highlight Ping Test on the Switch Utilities menu and press Enter ...

Page 132: ...kets to be sent 3 is usually enough Highlight START and press Enter to initiate the Ping program Layer 3 Utilities Layer 3 IP Routing switch operation mode adds BOOTP DHCP Relay and DNS Relay to the utilities available on the Switch BOOTP DHCP Relay To enter the IP addresses of BOOTP DHCP Relay servers highlight Utilities on the Main Menu and pressEnter ...

Page 133: ...on the Switch Utilities menu and pressEnter Figure 6 73 BOOTP DHCP Relay screen Toggle between Enabled and Disabled in the first field The BootP hops count limit allows the maximum number of hops routers that the BootP messages can be relayed through to be set If a packet s hop count is more than the hop count ...

Page 134: ...n the Switch Utilities menu and pressEnter Figure 6 74 BOOTP DHCP Relay Interface Configuration screen The Action field can be toggled between Add and Delete using the space bar Toggle to Add and enter the subnet name for which BOOTP Relay will be active The subnet s network IP address will be displayed in the IP Addr field Enter the IP address of the BOOTP DHCP server or servers as the case may b...

Page 135: ...ired The DNSR Cache Status Disabled can be toggled between Disabled and Enabled This determines if a DNS cache will be enabled on the switch The DNSR Static Table Lookup Status Disabled can be toggled between Disabled and Enabled This determines if the static DNS table entered on the DNS Relay Static table configuration screen below will be used or not To make a static DNS table entry highlight St...

Page 136: ...er the Domain name and its corresponding IP address Highlight APPLY and press Enter to make the change current Use Save Changes to enter the table into NV RAM Network Monitoring The DGS 3308 provides extensive network monitoring capabilities Layer 2 Network Monitoring To display the network data compiled by the Switch highlight Network Monitoring on the Main Menu and press Enter ...

Page 137: ...ernet Switch User s Guide 127 Figure 6 77 Network Monitoring Menu Port Utilization To view the port utilization highlight Port Utilization on the Network Monitoring Menu and pressEnter Figure 6 78 Port Utilization screen ...

Page 138: ...or Packets To view the error statistics for a port highlight Port Error Packets on the Network Monitoring Menu and press Enter Figure 6 79 Port Error Packets screen Enter the port number of the port to be viewed The Interval 2 sec field can be toggled from 2 seconds to 1 minute or Suspend This sets the interval at which the error statistics are updated Port Packet Analysis Table To view an analysi...

Page 139: ... port statistics on the number of unicast multicast and broadcast packets are displayed Enter the port number of the port to be viewed The Interval 2 sec field can be toggled from 2 seconds to 1 minute or Suspend MAC Address Forwarding Table To view the MAC address forwarding table highlight Browse MAC Address Table on the Network Monitoring Menu and pressEnter ...

Page 140: ...etermine which MAC addresses from the forwarding table are displayed ALL specifies no filter To search for a particular MAC address t oggle the Browse By ALL field to MAC Address A MAC Address 000000000000 field will appear Enter the MAC address in the field and pressEnter IGMP Snooping To view the IGMP snooping table h ighlight IGMP Snooping from the Network Monitoring Menu and press Enter ...

Page 141: ...thernet Switch User s Guide 131 Figure 6 82 IGMP Snooping screen Switch History To view the switch history log highlight Switch History from the Network Monitoring Menu and pressEnter Figure 6 83 Switch History screen ...

Page 142: ...following items are added to the Network Monitoring Menu when the Switch is in Layer 3 IP Routing mode Browse IP Address Routing Table ARP Table IP Multicast Forwarding Table IGMP Group Table DVMRP Routing Table Figure 6 84 Network Monitoring Menu Browse IP Address To view the IP address forwarding table highlight Browse IP Address from the Network Monitoring Menu and press Enter ...

Page 143: ... Address screen To display a particular IP address enter the IP address in the Jump to IP Address 0 0 0 0 field highlight GO and press Enter IP Routing Table To view the contents of the routing table highlight Routing Table on the Network Monitoring Menu and press Enter ...

Page 144: ...address in the Jump to Destination Address 0 0 0 0 field the gateway address in the Gateway 0 0 0 0 field and the subnet mask in the Mask 0 0 0 0 field highlight GO and press Enter Highlighting CLEAR TABLE and pressing Enter will empty the table ARP Table To view the ARP table highlight ARP Table on the Network Monitoring Menu and pressEnter ...

Page 145: ...er the IP interface name in the Jump to Interface Name field and the IP address in the IP Address 0 0 0 0 field highlight GO and press Enter Highlighting CLEAR TABLE and pressing Enter will empty the table Browse Router Port To view the current router ports highlight Browse Router Port from the Network Monitoring Menu and press Enter ...

Page 146: ...To display a particular router port enter the VLAN ID number in the Jump to VID 0 0 0 0 field highlight GO and then press Enter IP Multicast Forwarding Table To view the IP multicast forwarding table Highlight IP Multicast Forwarding Table from the Network Monitoring Menu and pressEnter ...

Page 147: ... group enter the IP address in the Jump to Multicast Group 0 0 0 0 field the source IP address in the Source IP 0 0 0 0 field and the source subnet mask in the Source Mask 0 0 0 0 field highlight GO and press Enter IGMP Group Table To browse the IGMP Group Table highlight IGMP Group Table from the Network Monitoring Menu and press Enter ...

Page 148: ... IGMP Group Table enter the name of the routing interface in the Jump to Interface Name 0 0 0 0 and the Multicast Group in the second field highlightGO and press Enter DVMRP Routing Table To view the DVMRP routing table highlight DVMRP Routing Table from the Network Monitoring Menu and press Enter ...

Page 149: ...er the IP address in the Jump to IP Address 0 0 0 0 field the source subnet mask in the Source Mask 0 0 0 0 field highlight GO and press Enter Highlighting CLEAR TABLE and pressing Enter will empty the table Reboot and Factory Reset To access the reboot save and factory reset options highlight Reboot on the Main Menu and pressEnter ...

Page 150: ... saves the configuration to NV RAM identical to using Save Changes and then restarts the switch Reboot Load Factory Default Configuration restarts the switch using the default factory configuration All configuration data will be lost This is identical to using Factory Reset and then Reboot Reboot Load Factory Default Configuration Except IP Address restarts the switch using the default factory con...

Page 151: ...Ethernet Switch User s Guide 141 Figure 6 93 Reboot screen To reboot the Switch in the mode entered above highlightYes and press Enter Note The factory defaults for the DGS 3308 are listed in Appendix D of this manual ...

Page 152: ... Changes from the Main Menu are retained in the switch s memory when the operational mode is changed IP Routing mode settings are simply inactive when the switch is in Layer 2 Only mode Before You Start The DGS 3308 Gigabit Ethernet Layer 3 Switch supports a wide array of functions and gives great flexibility and increased network performance by eliminating the routing bottleneck between the WAN o...

Page 153: ...nd users Further layer 3 VLANs are assigned an IP network address and subnet mask to enable IP routing between them Layer 3 VLANs must be configured on the switch before they can be assigned IP subnets Further the static VLAN configuration is specified on a per port basis On the DGS 3308 a VLAN can consist of end nodes just like a traditional layer 2 switch but a VLAN can also consist of one or mo...

Page 154: ...r the browser The second and last step is to configure the IP interface of the Switch This can be done manually through a console see the Configure IP Address section in chapter 6 Using The Console Interface To begin managing your Switch simply run the browser you have installed on your computer and point it to the IP address you have defined for the device The URL in the address bar should read s...

Page 155: ...e Save Changes command on the Maintenance menu if you want these changes to be permanent Root User and Normal User Privileges There are three levels of user privileges Root User and User Some menu selections available to users with Root privileges may notbe available to those with User and User privileges The following table summarizes the Root User and User privileges Switch Configuration Privile...

Page 156: ...will take effect Restarting the Switch erases all settings in RAM and reloads the stored settings from the NV RAM Thus it is necessary to save all setting changes to NV RAM before rebooting the Switch To retain any configuration changes permanently highlightSave Changes from the Maintenance menu The following screen will appear to verify that your new settings have been saved to NV RAM Figure 7 4 ...

Page 157: ...sword In addition several other parameters may need to be configured or known to properly communicate with the switch or allow full management capability These include Default Gateway Trap Destination and Community Name Configuration of these items may be made from the User Interface which is accessible via either the serial console or Telnet Refer to the User Guide that came with your system for ...

Page 158: ... parameters governing the SNMP agent You should therefore assign a password to the default administrator as soon as possible and store it in a safe place Setting Trap Destinations If you wish to record SNMP traps or events generated by the Switch you must configure a destination for the IP Trap Managers A trap destination is the IP address of the computer system on which the Web based manager is b...

Page 159: ... 3 The screen below will appear prompting you to enter the user name and password for management access Figure 7 7 Enter Network Password screen Use of the correct User Name and Password will allow read write access to the Switch The full application will now launch A three frame page will display including a view of the front panel in the top frame 4 To stop the Web based manager close the Web br...

Page 160: ...the Switch s ports and expansion modules showing port activity duplex mode or flow control depending on the specified mode Various areas of the graphic can be selected for performing management functions including the ports expansion modules management module or the case 2 Allows the selection of commands 3 Presents switch information based on your selection and the entry of configuration data Con...

Page 161: ...8 port Gigabit Ethernet Switch User s Guide 151 ...

Page 162: ...8 port Gigabit Ethernet Switch User s Guide 152 Layer 2 Mode ...

Page 163: ...8 port Gigabit Ethernet Switch User s Guide 153 ...

Page 164: ...8 port Gigabit Ethernet Switch User s Guide 154 ...

Page 165: ...yer 2 mode only IP Address Allows the manual input of an IP address for the Switch Subnet Mask Allows the input of a Subnet Mask Default Gateway Allows the input of the IP address of a Default Gateway used to pass trap messages from the Switch s agent to the management station Note that the gateway must be defined if the management station is located on a different IP segment than the Switch VID A...

Page 166: ...ardware version of the main board Device S N The factory assigns each Switch a unique serial number System Name Name assigned to the switch system System Location1 Specifies the area or location where the system resides System Contact1 Contact person for the system 1Maximum string length is 99 but the screen only displays 45 characters You can use the arrow keys to browse the whole string Power Su...

Page 167: ... more than one port at a time use the Configure Port from 1 to drop down list at the bottom of the panel and then click Apply Figure 7 12 Configure Port screen Items on the screen above include Port Type A read only field that indicates the type of port currently selected Connection A read only field that indicates the current status of the selected port State Allows the currently selected port to...

Page 168: ...pported and the switch is considered as a VLAN tag aware device The Switch must be rebooted when changing the operation mode before the new operation mode can take effect Switch Operation Mode The field Restart Mode can be set using the drop down menu on the Switch Operation Mode screen under Switch Settings on the Configuration menu to one of the two switch operation modes Layer 2 Only Support IE...

Page 169: ... s reaction to a Broadcast Multicast storm Configure Layer 3 IP Networking Routing Protocols Setup RIP The Routing Information Protocol RIP is a distance vector protocol that uses the hop count as its criteria for making routing decisions RIP is an Interior Gateway Protocol IGP which means that it performs routing within a single autonomous system Figure 7 15 Setup RIP screen Items on the screen a...

Page 170: ... for this RIP entry if applicable Tx Mode Allows transmitted RIP packets to be structured asRip V1 V1 Compatible Rip V2 or Disabled This entry specifies which version of the RIP protocol will be used to transmit RIP packets Disabled prevents the transmission of RIP packets Rx Mode Determines how received RIP packets will be interpreted as RIP version Rip V1 Rip V2 V1 and V2 or Disabled This entry ...

Page 171: ...bnet mask IP Address The IP address of the IP interface sometimes referred to as a network address Subnet Mask The subnet mask corresponding to the IP address and IP interface name VID The VLAN ID of the VLAN corresponding to this IP interface Active Displays whether the IP interface is active or inactive New A link to the IP Subnet Add menu Delete Click this icon to delete an IP subnet from this ...

Page 172: ...ection of ports to be members of this IP interface and its corresponding VLAN VLANs The following section describes how to set up IEEE 802 1Q VLANs on the Switch Figure 7 19 Edit 802 1Q VLANs screen Items on the screen above include VLAN ID VID The VLAN ID of the VLAN on which the static router port resides VLAN Name The name of the VLAN for which ports are to be configured New A link to the 802 1...

Page 173: ...ill designate the port as Tagging None Specifies the port as not being a static member of the VLAN but with no restrictions for joining the VLAN dynamically through GVRP Egress Specifies the port as being a static member of the VLAN Egress Member Ports are ports that will be transmitting traffic for the VLAN Forbidden Specifies the port as not being a static member of the VLAN and as being forbidd...

Page 174: ...the two are unequal the port will drop the packet If the two are equal the port will receive the packet Figure 7 22 Port VLAN ID PVID screen Description of item on the screen above PVID Shows the current PVID assignment for each port The Switch s default is to assign all ports to the Default_VLAN with a VID of 1 Port Ingress Filter The following window allows you to configure a Port Ingress Filter...

Page 175: ... be Enabled or Disabled Port GMRP Settings The following read only window is used to configure the Port Group Multicast Registration Protocol GMRP on the Switch This function is not supported in the current version of the Switch software Figure 7 25 Port GMRP Settings screen Items on the screen above include Port The number of the port for which GMRP is to be Enabled or Disabled GMRP For each corr...

Page 176: ...at can join the multicast group dynamically using GMRP The options are None no restrictions on the port dynamically joining the multicast group Egress the port is a static member of the multicast group and Forbidden the port is restricted from joining the multicast group dynamically For example if None is chosen then an end station attached to the port can join the multicast group using GMRP IGMP ...

Page 177: ...ticast interface Layer 3 mode only Figure 7 28 Multicast Interface Configuration screen Items on the screen above include Interface Name The name of the IP interface previously defined on the Switch for which a multicast interface is to be configured IP Address The IP address sometimes referred to as a network address that corresponds to the interface name above IGMP Allows IGMP to be Enabled or D...

Page 178: ...al The time in seconds between the transmission of IGMP query packets Max Resp The maximum number of respondents to an IGMP query Range is between 1 and 25 Robustness Var The Robustness Variable is a numeric value between 1 and 255 defining the maximum time in seconds between the receipt of IGMP queries If this timer expires without the receipt of another IGMP query the Switch assumes the queerer ...

Page 179: ...g window allows you to add an IGMP static member Click on the Exit icon to return to the main IGMP Static Member Configuration window Figure 7 31 IGMP Static Member Configuration Add screen Items on the screen above include Interface Name The name of the IP interface that the IGMP static member will belong to IGMP Static Group The IP address of the IGMP static group IGMP Static Group MAC Addr The ...

Page 180: ...al This field allows an entry between 1 and 65 535 seconds and defines the time period for which DVMRP will hold Neighbor Router reports before issuing poison route messages The default is 35 seconds Route Metric Allows the assignment of a DVMRP route cost to the above IP interface A DVMRP route cost is a relative number that represents the real cost of using this route in the construction of a mu...

Page 181: ... transmitting Hello messages to advertise its availability to become the root router The default is30 seconds Join Prune Interval This field allows an entry of between 1 and 18 724 seconds and determines the interval between transmitting flooding to all interfaces multicast messages to downstream routers and automatically pruning a branch from the multicast delivery tree This interval also determi...

Page 182: ...dd a Static Router Port The following figure and table describe how to add a static router port on the Switch Click on the Exit icon to return to the Static Router Port Settings window Figure 7 35 Setup Static Router Port Add screen Items on the screen above include VID The VLAN ID of the VLAN on which the static router port resides Port Member Click the box corresponding to the port that will be ...

Page 183: ...h the above MAC address will be given the selected priority Entries VID Displays the VLAN ID of the VLAN on which the MAC address above resides MAC Address Displays the MAC address for which priority on the Switch is to be established Priority Level Displays the priority of the above MAC address The options are Low Med L medium low Med H medium high and High Src Dst Displays the state under which ...

Page 184: ... Selection screen The item on the screen above includes Target Port The port that will receive the packets duplicated at the mirror port Port Mirroring Settings The following window is used in setting up a mirror port for port mirroring A mirror port is the port of a target mirror pair that will have its traffic duplicated and forwarded to the target port Figure 7 38 Port Mirroring Settings screen...

Page 185: ...work loops and to provide backup links between switches bridges or routers This allows the Switch to interact with other bridging devices that is STP compliant switches bridges or routers in your network to ensure that only one route exists between any two stations on the network For a more detailed description of how to use this protocol refer to Spanning Tree Concepts in Chapter Five STP Group C...

Page 186: ...f it is a root port a new root port is selected from among the device ports attached to the network The minimum value is the higher of 6 or 2 x Hello Time 1 The maximum value is the lower of 40 or 2 x Forward Delay 1 Hello Time 1 10 sec The time interval in seconds at which the root device transmits a configuration message Forward Delay 4 30 sec The maximum time in seconds the root device will wai...

Page 187: ...ity becomes the STP root device The lower the numeric value the higher the priority If all devices have the same priority the device with the lowest MAC address will become the root device Port Member Check the ports you want to be member of the STP group STP Group Configuration Edit The following window is used to configure Spanning Tree Protocol STP for a group on the Switch ...

Page 188: ...e interval in seconds at which the root device transmits a configuration message Forward Delay 4 30 sec The maximum time in seconds the root device will wait before changing states i e from the listening to learning to forwarding This delay is required because every device must receive information about topology changes before it starts to forward packets In addition each port needs time to listen...

Page 189: ...nnection or to ensure fault recovery You can configure up to 4 trunk connections combining 2 to 8 ports into a fat pipe between any two DGS 3308 or other Layer 2 switches However before making any physical connections between devices use the Trunk Configuration menu to specify the trunk on the devices at both ends When using a port trunk note that The ports used in a trunk must all be of the same ...

Page 190: ...o be configured The group number identifies each of these groups Master Port The port of the trunk group whose configuration speed full or half duplex etc will be used by all of the ports in the trunk group Group Width The number of contiguous ports in the selected trunk group Method Allows the trunk group to be Enabled or Disabled Anchor This port displays what port is receiving BPDUs SNMP packet...

Page 191: ...the designation of the port on which the above MAC address resides Entries MAC Address Displays the MAC address corresponding to the static forwarding table entry VID Displays the VLAN ID number of the VLAN to which the above MAC address belongs PortMap Displays the port on which the above MAC address resides IP Forwarding The following window isused for the entry of a Static Default Routes into t...

Page 192: ...Add The following figure and table describe the entry of a Static Default Route into the Switch s IP routing table Click on the Exit icon to return to the Static Default Routes window Figure 7 46 Static Default Routes Add screen Items on the screen above include IP Address The IP address to be statically entered into the IP forwarding table Subnet Mask The corresponding subnet mask for the IP addr...

Page 193: ...w A link to the Static ARP Add window Delete Click on the icon to delete the static ARP entry Static ARP Add The following figure and table describe adding an entry to the Switch s static ARP table Click on the Exit icon to return to the Static ARP menu Figure 7 48 Static ARP Add screen Items on the screen above include Interface Name The IP interface on which the IP address to be added to the sta...

Page 194: ... address as their destination will be dropped When Src is chosen packets which the above MAC address as their source will be dropped When Either is chosen all packets to or from the above MAC address will be dropped by the Switch Entries VID Displays the VLAN ID number of the VLAN on which the MAC address resides MAC Address Displays the MAC address that is to be filtered on the Switch Src Dst Dis...

Page 195: ...ther either a destination or a source address Delete Click the icon to remove the entry from the filtering table BOOTP DHCP Relay BOOTP DHCP relay enables end stations to use a BOOTP or DHCP server to obtain TCP IP configuration information or boot files to be loaded into memory even if the servers are not on the local IP interface If the BOOTP or DHCP server and end station are on the same IP int...

Page 196: ...HCP Relay Time Threshold Sets the minimum time in seconds that the switch will wait before forwarding a BOOTREQUEST packet If the value in the seconds field of the packet is less than the relay time threshold the packet will be dropped The range is between 0 and 65 536 seconds The default value is 0 seconds BOOTP DHCP Relay Interface Setup The second task is to tell the BOOTP DHCP relay agent wher...

Page 197: ... the DNS servers and their respective subnet names or IP interface names When the switch receives packets destined for a DNS server it forwards them to specific servers as defined in the following configuration The Switch also forwards packets from the DNS servers to the appropriate subnets The first task is to set some parameters for the relay agent to decide whether or not to forward a given DNS...

Page 198: ...indows which are the same whether the Switch is in Layer 2 mode or Layer 3 mode to configure the IP addresses of up to 3 Management stations to configure SNMP Community strings to enter the IP addresses of Trap receivers to create and manage user accounts and to configure the Serial Port settings Management Station IP Settings You can specify the IP addresses of up to 3 management stations that wi...

Page 199: ...gent that monitors the status of its hardware as well as the traffic passing through its ports A computer attached to the network called a Network Management Station NMS can be used to access this information Access rights to the on board agent are controlled by community strings To communicate with the switch the NMS must first submit a valid community string for authentication The following wind...

Page 200: ...other trap messages from the Switch Up to 4 trap managers may be entered Figure 7 57 Setup Trap Receivers screen Items on the screen above include IP Address The IP address of the management station that will receive traps generated by the Switch SNMP Community String A string of up to 20 characters used for authentication of users wanting to receive traps from the Switch s SNMP agent Status Speci...

Page 201: ...initial password and then confirm the new password Determine whether the new user should have Root User or User privileges Click on Apply to make the user addition effective A listing of all user accounts and access levels is shown on the Setup User Accounts table This list is updated when Apply is executed Please remember that Apply makes changes to the switch configuration for the current sessio...

Page 202: ...the Maintenance menu if you want these changes to be permanent Serial Port Settings The following screens are used to configure the Switch s serial port sometimes referred to as a console port Figure 7 61 Serial Port Settings screen Items on the screen above include Console Settings Baud Rate Specifies the rate data will be exchanged over the serial link The default value is 9600 baud Data Bits Sp...

Page 203: ...statistics are compiled by the Switch s management agent Figure 7 62 Port Utilization screen The statistic counters displayed are defined as follows Update Interval The interval in seconds that the table is updated The default isSuspend TX frames sec The number of good bytes sent from the respective port per second RX frames sec The number of good bytes received per second This also includes local...

Page 204: ...number of frames received that were less than 64 octets long excluding framing bits but including FCS octets and were otherwise well formed Oversize The total number of frames received that were longer than 1518 octets excluding framing bits but including FCS octets and were otherwise well formed Fragments The total number of frames received that were less that 64 octets in length excluding framin...

Page 205: ...llisions The number of times that a collision is detected later than 512 bit times into the transmission of a packet Ex Coll Excessive Collisions The number of frames for which transmission failed due to excessive collisions Single Coll Single Collision Frames The number of successfully transmitted frames for which transmission is inhibited by more than one collision Coll An estimate of the total ...

Page 206: ...ng size indicated Packet Type Rx This displays both the bytes and frames received Packet Type Tx This displays both the bytes and frames transmitted Clear Click this button to clear all counters Port Utilization History The Switch allows you to display a graphical representation of a selected port s utilization These figures are the percentage of bandwidth being used Figure 7 65 Switch Overview sc...

Page 207: ... s Guide 197 Address Table The following section describes how to browse the Switch s address tables Browse MAC Address Table The Web Manager allows the Switch s MAC address table sometimes referred to as a forwarding table to be viewed ...

Page 208: ...that is how long a learned MAC Address is allowed to remain idle The Aging Time can be set to any value between 10 and 1 000 000 seconds VID The VLAN ID of the VLAN the port is a member of MAC Address The MAC address entered into the address table Port The port that the MAC address above corresponds to Learned How the Switch discovered the MAC address The possible entries are Dynamic Self and Stat...

Page 209: ...er s Guide 199 Figure 7 67 IP Address Table screen To display a particular IP address enter the IP address in the Jump to IP Address field and click GO Routing Table The Web Manager allows you to view the contents of the routing table ...

Page 210: ...Routing Table screen To display a particular Destination IP address enter the IP address netmask and default gateway in the three fields above and then click Go Clicking Clear Table will empty the table ARP Table The Web Manager allows you to view the ARP table ...

Page 211: ...P interface name in the first field the IP address in the second field and then click Go Clicking Clear Table will empty the table Applications The following figures and tables describe the applications available when using the Web based manager GVRP The following read only table displays current GVRP information ...

Page 212: ... ports of a multicast enabled router Routers do not implement IGMP snooping or transmit forward IGMP report packets Thus forwarding all IP UDP multicast packets to a static router port guarantees that all ports of a multicast enabled router attached to the Switch can reach all multicast group members through the attached router s other ports The Switch monitors each port for UDP multicast packets ...

Page 213: ...oping Table for the current VID Multicast Group The IP address of a multicast group learned by IGMP snooping MAC Address The corresponding MAC address learned by IGMP snooping Port Map Displays the ports that have forwarded multicast packets from the above source Reports The number of IGMP reports for the listed source IP Multicast Forwarding Table The Web Manager allows you to view the IP multica...

Page 214: ...icast group in the first two fields and then click Go DVMRP Routing Table The Web Manager allows you to display a DVMRP routing table Figure 7 75 DVMRP Routing Table screen To display a DVMRP routing entries enter the IP address and source subnet mask in the first two fields and click GO Clicking Clear Table will empty the table Switch History The Web based manager allows the Switch s history log ...

Page 215: ...Text Displays text describing the event that triggered the history log entry Maintenance The Maintenance menu which is the same whether the Switch is in Layer 2 mode or Layer 3 mode offers a range of utilities including various TFTP services Trivial File Transfer Protocol TFTP services allow the Switch firmware to be upgraded by downloading a new firmware file from a TFTP server to the Switch A co...

Page 216: ...ncluding path of the new firmware file on the TFTP server Download Configuration File from TFTP Server A configuration file can be downloaded from a TFTP server to the Switch This file is then used by the Switch to configure itself Figure 7 78 Download Configuration File from TFTP Server screen Items on the screen above include Server IP Address The IP address of the TFTP server Path and File Name...

Page 217: ...an upload its history log file to a TFTP server Figure 7 80 Save Log To TFTP Server screen Items on the screen above include Server IP Address The IP address of the TFTP server Path and File Name The full file name including path of the history file on the TFTP server Save Changes The DGS 3308 has two levels of memory normal RAM and non volatile or NV RAM To retain any configuration changes perman...

Page 218: ... the Switch using only the configuration that was supplied by the factory A factory reset returns all configuration options to their default values and restores the Switch s configuration to the factory settings All user entered configuration information will be lost Figure 7 82 Factory Reset screen Click Yes if you want the Switch to retain its current IP address Click No to reset the Switch s IP...

Page 219: ... is used to restart reboot the Switch Click Yes to save the current Switch configuration to non volatile RAM flash RAM or No if you wantto restart the Switch using the last saved previous configuration Click the Restart button to restart the Switch Figure 7 83 Restart System screen ...

Page 220: ...802 1 P Q VLAN IEEE 802 3x Full duplex Flow Control ANSI IEEE 802 3 NWay auto negotiation Protocols CSMA CD Data Transfer Rates Ethernet Fast Ethernet Gigabit Ethernet Half duplex Full duplex 10 Mbps 20Mbps 100Mbps 200Mbps n a 2000Mbps Topology Star Network Cables 10BASE T 100BASE TX 100BASE FX 1000BASE SX 2 pair UTP Cat 3 4 5 100 m EIA TIA 568 100 ohm STP 100 m 2 pair or 4 pair UTP Cat 5 100 m EI...

Page 221: ...m DC fans 3 built in 40 x 40 x10 mm fans Operating Temperature 0 to 50 degrees Celsius Storage Temperature 25 to 55 degrees Celsius Humidity Operating 5 to 95 RH non condensing Storage 0 to 95 RH non condensing Dimensions 441 mm x 210 mm x 43 mm 1U 19 inch rack mount width Weight 2 6 kg EMI FCC Class A CE Mark VCCI Class 1 BSMI Class A C Tick Class A Safety UL CUL TUV GS Performance Transmission M...

Page 222: ...8 port Gigabit Ethernet Switch User s Guide 212 Performance Forwarding Table Age Time Max age 10 1000000 seconds Default 300 IP Address 2K per device ...

Page 223: ... is necessary Please review the following for matching cable pin assignment Figure B 1 The standard RJ 45 receptacle connector RJ 45 Connector pin assignment Contact Media Direct Interface Signal 1 Tx transmit 2 Tx transmit 3 Rx receive 4 Not used 5 Not used 6 Rx receive 7 Not used 8 Not used Table B 1 The standard Category 3 cable RJ 45 pin assignment ...

Page 224: ...P service Disable TFTP server IP address 0 0 0 0 IGMP Snooping Disable Console time out 10 min User name None Password None Device STP Enable Port STP Enable Port enable Enable Bridge max age 20 secs Bridge hello time 2 sec Bridge forward delay 15 sec Bridge priority 32768 Port STP cost 19 Gigabit 10 Port STP priority 128 Forwarding table aging time 300 secs Nway Enable Flow control Enable Broadca...

Page 225: ...re enabled At this point packets are forwarded by the port Blocking State A port in the blocking state does not forward packets When the switch is booted a BPDU is sent to each port in the switch putting these ports into the blocking state A switch initially assumes it is the root and then begins the exchange of BPDUs with other switches This will determine which switch in the network is the best ...

Page 226: ...the blocking state that is a different port is a better choice There is no address learning or packet forwarding from a port in the listening state A port in the listening state does the following Discards frames received from the network segment to which it is attached Discards packets sent from another port on the switch for forwarding Does not add addresses to its forwarding database Receives B...

Page 227: ...from the network segment to which it is attached Discards packets sent from another port on the switch for forwarding Adds addresses to its forwarding database Receives BPDUs and directs them to the CPU Processes and transmits BPDUs received from the CPU Receives and responds to network management messages Forwarding State A port in the forwarding state forwards packets The port enters the forward...

Page 228: ...n information into its address database Receives BPDUs and directs them to the system CPU Receives and responds to network management messages Disabled State A port in the disabled state does not participate in frame forwarding or STP A port in the disabled state is virtually non operational A disabled port does the following Discards packets received from the network segment to which it is attach...

Page 229: ...ystem CPU Does not receive BPDUs for transmission from the system CPU Receives and responds to network management messages Troubleshooting STP Spanning Tree Protocol Failure A failure in the STA generally leads to a bridging loop A bridging loop in an STP environment comes from a port that should be in the blocking state but is forwarding packets ...

Page 230: ...blocking state to the forwarding state It should be noted A port must continue to receive BPDUs advertising superior paths to remain in the blocking state There are a number of circumstances in which the STA can fail mostly related to the loss of a large number of BPDUs These situations will cause a port in the blocking state to transition to the forwarding state Full Half Duplex Mismatch A mismat...

Page 231: ... port 2 on B it will transition to the forwarding state If the failure exists at boot STP will not converge and rebooting the bridges will have no effect Note Rebooting would help temporarily in the previous example This type of failure is difficult to detect because the Link state LEDs for Ethernet links rely on the transmit side of the cable to detect a link If a unidirectional failure on a link...

Page 232: ...e network at the same time a data loop can be suspected The port utilization data in the switch s console will give unusually high values in this case The priority for most cases is to restore connectivity as soon as possible The simplest remedy is to manually disable all of the ports that provide redundant links Disabling ports one at a time and then checking for a restoration of the user s conne...

Page 233: ...nks by default carry all the VLAN traffic from VLAN 1 and VLAN 2 So switch C is not only receiving traffic for VLAN 1 but it is also receiving unnecessary broadcast and multicast traffic for VLAN 2 It is also blocking one port for VLAN 2 Thus there a re three redundant paths between switches A and B and two blocked ports per VLAN This increases the chance of a data loop ...

Page 234: ...pact of Layer 3 Switching The IP routing operational mode of the DGS 3308FG DGS 3308TG Layer 3 switch can accomplish the following Building a forwarding table and exchanging information with its peers using routing protocols Receiving packets and forwarding them to the correct interface based upon their destination address With layer 3 switching there is no performance penalty to introducing a rou...

Page 235: ...es the need for STP port blocking because the packets are routed by destination addresses The link redundancy remains and relying on the routing protocols gives a faster convergence than with STP The drawback is that the introduction of layer 3 switching usually requires a new addressing scheme ...

Page 236: ...on compares 2 bits and if either or both bits are 1 then the result is 1 otherwise the result is 0 0 1 0 0 0 1 0 1 XOR The logical XOR exclusive OR operation compares 2 bits and if exactly one of them is a 1 then the result is 1 otherwise the result is 0 0 1 0 0 1 1 1 0 NOT The logical NOT operation simply changes the value of a single bit If it is a 1 the result is 0 if it is a 0 the result is 1 ...

Page 237: ... DVMRP Routing Table 209 Dynamic filtering 18 E Egress 166 Egress port 24 Ethernet protocol 6 Ex Coll 200 ExDefer 200 F Filtering 18 187 Flash memory 5 Forward Delay 33 180 182 Forwarding 18 184 Fragments 199 Front Panel 10 G gateway router 16 Gigabit Ethernet 6 H Hello Interval 175 Hello Time 33 114 180 182 Humidity 216 I IEEE 802 1Q VLANs 24 IGMP Group Table 209 IGMP Snooping 208 Illustration of...

Page 238: ...163 Setup RIP 162 Single Coll 200 Spanning Tree Algorithm 5 Spanning Tree Algorithm STA 29 Spanning Tree Protocol 19 Spanning Tree Protocol Configuration 178 Static Default Routes 185 Static ARP 186 Statistics 198 Storage Temperature 216 Store and forward switching 4 STP Port Settings 183 Subnet Mask 70 Switch History 209 Switch Operation Mode 161 System Information 158 T Tag 166 tagging 23 24 Tar...

Page 239: ... Egypt TEL 20 2 635 6176 FAX 20 2 635 6192 URL www dlink me com E MAIL support dlink me com fateen dlink me com Finland D Link Finland Thlli ja Pakkahuone Katajanokanlaituri 5 FIN 00160 Helsinki TEL 358 9 622 91660 FAX 358 9 622 91661 URL www dlink fi com France D Link France Le Florilege 2 Allee de la Fresnerie 78330 Fontenay le Fleury France TEL 33 1 3023 8688 FAX 33 1 3023 8689 URL www dlink fr...

Page 240: ... 0 12 665 2186 URL www d link co za E MAIL attie d link co za Spain D Link Iberia Gran Via de Carlos III 843º Edificio Trade 08028 Barcelona Spain TEL 34 93 4965751 FAX 34 93 4965701 URL www dlinkiberia es Sweden D Link Sweden P O Box 15036 S 167 15 Bromma Sweden TEL 46 0 8 564 61900 FAX 46 0 8 564 61901 E MAIL info dlink se URL www dlink se Taiwan D Link Taiwan 2F No 119 Pao Chung Rd Hsin Tien Ta...

Page 241: ...o support your product 1 Where and how will the product primarily be used oHome oOffice oTravel oCompany Business oHome Business oPersonal Use 2 How many employees work at installation site o1 employee o2 9 o10 49 o50 99 o100 499 o500 999 o1000 or more 3 What network protocol s does your organization use oXNS IPX oTCP IP oDECnet oOthers_____________________________ 4 What network operating system ...

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