background image

DES-3326S Layer 3 Fast Ethernet Switch User’s Guide 

Understanding and Troubleshooting the Spanning Tree Protocol 

327

 

 

 

Summary of Contents for DES-3326S - Switch - Stackable

Page 1: ...DES 3326S Layer 3 Switch User s Guide First Edition June 2001 651E3326S015 Printed In Taiwan RECYCLABLE...

Page 2: ...h am Ger ten befinden sind zu beachten 12 Wird das Ger t ber einen l ngeren Zeitraum nicht benutzt sollten Sie es vom Stromnetz trennen Somit wird im Falle einer berspannung eine Besch digung vermiede...

Page 3: ...18 Zum Netzanschlu dieses Ger tes ist eine gepr fte Leitung zu verwenden F r einen Nennstrom bis 6A und einem Ger tegewicht gr er 3kg ist eine Leitung nicht leichter als H05VV F 3G 0 75mm2 einzusetzen...

Page 4: ...ORY OF LIABILITY THIS LIMITATION WILL APPLY EVEN IF D LINK HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE IF YOU PURCHASED A D LINK PRODUCT IN THE UNITED STATES SOME STATES DO NOT ALLOW THE LIMITA...

Page 5: ...n Card for the product in question has not been returned to a D Link office then a proof of purchase such as a copy of the dated purchase invoice must be provided when requesting warranty service The...

Page 6: ...vi 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 7: ...nk 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...

Page 8: ...n 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...

Page 9: ...t Ethernet Technology 21 Gigabit Ethernet Technology 22 Unpacking and Setup 23 Unpacking 23 Installation 24 Desktop or Shelf Installation 24 Rack Installation 25 Power on 26 Power Failure 27 Identifyi...

Page 10: ...ostic console port RS 232 DCE 45 Managing Switch Stacks 46 Switch IP Address 49 Traps 50 SNMP 52 MIBs 55 Packet Forwarding 56 Filtering 57 Spanning Tree 59 Link Aggregation 70 VLANs 72 IP Addresses 81...

Page 11: ...215 IP Multicasting 237 Port Mirroring 251 Priority 253 Filtering 256 Forwarding 259 Spanning Tree 268 Link Aggregation 274 Utilities 277 Network Monitoring 287 Technical Specifications 316 Understand...

Page 12: ...xii Identifying a Data Loop 335 Avoiding Trouble 335 Brief Review of Bitwise Logical Operations 342 Index 344...

Page 13: ...s the integration of two proven technologies switching and routing In fact Layer 3 switches are running the same routing routines and protocols as traditional routers The main difference between tradi...

Page 14: ...of the network and providing 24 ports of Layer 2 switching performance combined with wire speed routing Backbone routers can also be replaced with DES 3326S and a series of DES 3326S could be linked...

Page 15: ...er does Determines forwarding path based on Layer 3 information Validates the integrity of the Layer 3 header via checksum Verifies packet expiration and updates accordingly Processes and responds to...

Page 16: ...IX function for connecting to end stations servers and hubs All ports can auto negotiate NWay between 10Mbps 100Mbps half duplex or full duplex and flow control for half duplex ports One front panel s...

Page 17: ...de ports Supports Back pressure flow control for half duplex mode ports Auto polarity detection and correction of incorrect polarity on the transmit and receive twisted pair at each port IEEE 802 3z c...

Page 18: ...ports Port Mirroring Supports Port Trunking up to six trunk groups each consisting of up to eight ports may be set up 802 1D Spanning Tree support 802 1Q Tagged VLAN support up to 63 User defined VLAN...

Page 19: ...upport RFC 1112 and RFC 2236 Supports PIM Dense Mode Supports DVMRP Supports IP multi netting Supports IP packet de fragmentation Supports 802 1D frame support Traffic Classification and Prioritizatio...

Page 20: ...band via TFTP or out of band via the console Built in SNMP management Bridge MIB RFC 1493 MIB II RFC 1213 Mini RMON MIB RFC 1757 4 groups CIDR MIB RFC 2096 except IP Forwarding Table 802 1p MIB RFC 26...

Page 21: ...anaged as a unit with a single IP address Management for the entire stack is done through the Master Switch You may add Switches later as needed Fast Ethernet Technology 100Mbps Fast Ethernet or 100BA...

Page 22: ...hernet Since it is compatible with all 10Mbps and 100Mbps Ethernet environments Gigabit Ethernet provides a straightforward upgrade without wasting a company s existing investment in hardware software...

Page 23: ...f the Switch and carefully unpack its contents The carton should contain the following items One DES 3226 24 port Fast Ethernet Layer 3 Switch Mounting kit 2 mounting brackets and screws Four rubber f...

Page 24: ...cord and see that it is secured to the AC power connector Make sure that there is proper heat dissipation from and adequate ventilation around the switch Do not place heavy objects on the switch Deskt...

Page 25: ...llation The DES 3326S can be mounted in an EIA 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 pane...

Page 26: ...on The DES 3326S switch can be used with AC power supply 100 240 VAC 50 60 Hz The power switch is located at the rear of the unit adjacent to the AC power connector and the system fan The switch s po...

Page 27: ...r is turned ON The console LED indicator will blink while the Switch loads onboard software and performs a self test will remain ON if there is a connection at the RS 232 port otherwise this LED indic...

Page 28: ...t panel of the Switch consists of LED indicators an RS 232 communication port a slide in module slot and 24 10 100 Mbps Ethernet Fast Ethernet ports Figure 3 1 Front panel view of the Switch Comprehen...

Page 29: ...orts all of which operate at 10 100 Mbps with Auto MDIX function for connections to end stations servers and hubs All ports can auto negotiate between 10Mbps or 100Mbps full or half duplex and flow co...

Page 30: ...em also provide heat vents to serve the same purpose Do not block these openings and leave at least 6 inches of space at the rear and sides of the switch for proper ventilation Be reminded that withou...

Page 31: ...odule 2Km 15Km Figure 3 5 100BASE FX two port module Front panel module Two 100BASE FX with SC type connector Fiber ports Fully compliant with IEEE802 3u Support Full duplex operation only IEEE 802 3x...

Page 32: ...ctions of up to 100 meters 1000BASE SX Fiber Module Figure 3 7 1000BASE SX two port module Front panel module Connects to 1000BASE SX devices at full duplex Allows connections using multi mode fiber o...

Page 33: ...insertion loss Unit dB 2 33 2 53 3 25 3 43 1000BASE LX Fiber Module Figure 3 8 1000BASE LX two port module Front panel module Connects to 1000BASE LX devices at full duplex Supports multi mode fiber...

Page 34: ...onnects to GBIC devices at full duplex only Allows multi mode fiber optic connections of up to 550 m SX and LX and single mode fiber optic connections of up to 5 km LX only GBIC modules are available...

Page 35: ...duplex Stacking Port One transmitting port and one receiving port Use the connector of IEEE 1394b Data rate up to 1250 Mbps 7 segment LED display to indicate switch ID number within the switch stack T...

Page 36: ...an IN port on one switch to an OUT port on the next switch in the stack The last two switches at the top and bottom of the stack must also be connected from the IN port on one switch to the OUT port...

Page 37: ...powered on to indicate the ready state of the device Console This indicator is lit green when the switch is being managed via out of band local console management through the RS 232 console port usin...

Page 38: ...switch A 0 a zero in the display indicates that the stacking module is in the process of determining the stack status and has not yet resolved the switch s Unit number The stacking order can be autom...

Page 39: ...routers The RJ 45 UTP ports on NICs and most routers are MDI II When using a normal straight through cable an MDI II port must connect to an MDI X port An end node can be connected to the Switch via...

Page 40: ...ator states are possible for an end node to switch connection 1 The 100 LED indicator comes ON for a 100 Mbps and stays OFF for 10 Mbps 2 The Link Act LED indicator lights up upon hooking up a PC that...

Page 41: ...a switch stack from the serial port on the master switch The CLI can also be used to configure and manage the switch stack via the TELNET protocol using a single IP address the IP address of the Mast...

Page 42: ...ide 42 Connecting The Switch Figure 4 Switch Stack connections between optional stacking modules 10BASE T Device For a 10BASE T device the Switch s LED indicators should display the following 100 LED...

Page 43: ...Layer 3 Fast Ethernet Switch User s Guide Connecting The Switch 43 100BASE TX Device For a 100BASE TX device the Switch s LED indicators should display the following 100 LED speed indicator is ON Link...

Page 44: ...ng the switch to implement these concepts and make use of its many features is discussed in detail in the next chapters Local Console Management A local console is a terminal or a workstation running...

Page 45: ...d management requires connecting a terminal such as a VT 100 or a PC running a terminal emulation program such as HyperTerminal which is automatically installed with Microsoft Windows a to the RS 232...

Page 46: ...when you are placing the Switches in the equipment rack Administrators may find it convenient to place the Switches in the rack in the same order they appear logically in the Switch stack However you...

Page 47: ...e MAC addresses see the following example Determining the Switch Stack Order Using the auto stacking mode five MAC addresses appear in the order listed in the table below Stack Order MAC Address 1 Mas...

Page 48: ...nformation on how to override the stack order auto detect function To override the automatic selection of the stack order you must attach the serial cable to the newly added Switch MAC address 0011223...

Page 49: ...P 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 addre...

Page 50: ...f System ipaddress xxx xxx xxx xxx yyy yyy yyy yyy Where the x s represent the IP address to be assigned to the IP interface named System and the y s represent the corresponding subnet mask 2 Alternat...

Page 51: ...and four corresponding SNMP community strings can be entered SNMP community strings function like passwords in that the community string entered for a given IP address must be used in the management...

Page 52: ...warding state to the Blocking state The trap is not sent if a new root trap is sent for the same transition Link Up This trap is sent whenever the link of a port changes from link down to link up Link...

Page 53: ...nt and the remote user SNMP application program discard packets from unauthorized users Authentication is accomplished using community strings which function like passwords The remote user SNMP applic...

Page 54: ...send to a trap recipient Cold Start This trap signifies that the Switch has been powered up and initialized such that software settings are reconfigured and hardware systems are rebooted A cold start...

Page 55: ...his trap is sent whenever the port reaches the threshold in packets per second set globally for the switch Counters are maintained for each port and separate counters are maintained for broadcast and...

Page 56: ...us If you use a third party vendors SNMP software to manage the Switch a diskette listing the Switch s propriety enterprise MIBs can be obtained by request If your software provides functions to brows...

Page 57: ...er 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 receiv...

Page 58: ...ilter packets based on topology making sure that signal loops don t occur Filtering done for VLAN integrity Packets from a member of a VLAN VLAN 2 for example destined for a device on another VLAN VLA...

Page 59: ...locked links at the time of a primary link failure is also accomplished automatically without operator intervention The DES 3326S STP allows two levels of spanning trees to be configured The first lev...

Page 60: ...768 Hello Time The length of time between broadcasts of the hello message by the switch 2 seconds Maximum Age Timer Measures the age of a received BPDU for a port and ensures that the BPDU is discarde...

Page 61: ...o arrive at a stable network topology the following information is used The unique switch identifier The path cost to the root associated with each switch port The port identifier STP communicates bet...

Page 62: ...ts will be forwarded to the root A port for each switch is selected This is the port providing the best path from the switch to the root switch Ports included in the STP are selected Creating a Stable...

Page 63: ...imer is used to allow the network topology to stabilize after a topology change In addition STP specifies a series of states a port must transition through to further ensure that a stable network topo...

Page 64: ...erating Concepts From initialization switch boot to blocking From blocking to listening or to disabled From listening to learning or to disabled From learning to forwarding or to disabled From forward...

Page 65: ...bled for that port Default Spanning Tree Configuration Feature Default Value Enable state STP enabled for all ports Port priority 128 Port cost 19 Bridge Priority 32 768 Table 5 7 Default STP Paramete...

Page 66: ...ll start sending its own BPDU to all other Switches for permission to become the Root Bridge If it turns out that your Switch has the lowest Bridge Identifier it will become the Root Bridge Forward De...

Page 67: ...ure 2 4 In this example STP breaks the loop by blocking the connection between Bridge B and C The decision to block a particular connection is based on the STP calculation of the most current Bridge a...

Page 68: ...DES 3326S Layer 3 Fast Ethernet Switch User s Guide 68 Switch Management and Operating Concepts Figure 5 3 Before Applying the STA Rules In this example only the default STP values are used...

Page 69: ...high port cost between switches B and C The two optional Gigabit ports default port cost 10 on switch A are connected to one optional Gigabit port on both switch B and C The redundant link between sw...

Page 70: ...nk aggregation group must be configured to operate in the same manner the configuration of the master port is applied to all members of the link aggregation group Thus when configuring the ports in a...

Page 71: ...link aggregation group This allows packets in a data stream to arrive in the same order they were sent A aggregated link connection can be made with any other switch that maintains host to host data...

Page 72: ...The DES 3326S supports IEEE 802 1Q VLANs The port untagging function can be used to remove the 802 1Q tag from packet headers to maintain compatibility with devices that are tag unaware that is netwo...

Page 73: ...VLANs are implemented on the DES 3326S Layer 3 switch 802 1Q VLANs require tagging which enables the VLANs to span an entire network assuming all switches on the network are IEEE 802 1Q compliant Any...

Page 74: ...N Tags The figure below shows the 802 1Q VLAN tag There are four additional octets inserted after the source MAC address Their presence is indicated by a value of 0x8100 in the EtherType field When a...

Page 75: ...12 bits long 4094 unique VLANs can be identified The tag is inserted into the packet header making the entire packet longer by 4 octets All of the information contained in the packet originally is ret...

Page 76: ...ortunately not all network devices are 802 1Q compliant These devices are referred to as tag unaware 802 1Q devices are referred to as tag aware Prior to the adoption 802 1Q VLANs port based and MAC b...

Page 77: ...ed a PVID but the PVID is not used to make packet forwarding decisions the VID is Tag aware switches must keep a table to relate PVIDs within the switch to VIDs on the network The switch will compare...

Page 78: ...ts received by and forwarded by an untagging port will have no 802 1Q VLAN information Remember that the PVID is only used internally within the switch Untagging is used to send packets from an 802 1Q...

Page 79: ...by dropping packets that are not on the same VLAN as the ingress port at the point of reception This eliminates the subsequent processing of packets that will just be dropped by the destination port V...

Page 80: ...ts a packet s IP address to determine VLAN membership no route calculation is performed the RIP protocol is not employed and packets traversing the switch are bridged using the Spanning Tree algorithm...

Page 81: ...mask Subnet Address another name for network address IP Addresses The Internet Protocol IP was designed for routing data between network sites Later it was adapted for routing between networks referre...

Page 82: ...11110001 00111000 3 01111101 01010111 00000000 00000001 The dots are included to make the numbers easier to read Eight binary bits are called a byte or an octet An octet can represent any decimal valu...

Page 83: ...an IP address Address Classes Address classes refer to the range of numbers in the subnet mask Grouping the subnet masks into classes makes the task of dividing a network into subnets a bit easier Th...

Page 84: ...the address is the last three octets x 42 73 210 To specify the network address for a given IP address the node part is set to all 0 s In our example 10 0 0 0 specifies the network address for 10 42 7...

Page 85: ...l network when a host does not know it s network address and for all hosts on the network the broadcast address This also applies to subnets A subnet address cannot be all 0 s or all 1 s A 1 bit subne...

Page 86: ...0 possible nodes Note that this is less than the 16 777 214 possible nodes that an unsubnetted class A network would have Subnetting reduces the number of possible nodes for a given network but increa...

Page 87: ...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...

Page 88: ...6 2 62 124 3 255 255 255 224 27 6 30 180 4 255 255 255 240 28 14 14 196 5 255 255 255 248 29 30 6 180 6 255 255 255 252 30 62 2 124 Table 5 11 Class C Subnet Masks Setting up IP Interfaces The Layer 3...

Page 89: ...0 xxx xxx xxx IP address notation the above example would give 6 network addresses and 6 subnets Any IP address from the allowed range of IP addresses for each subnet can be chosen as an IP address fo...

Page 90: ...or each 802 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 protocol is not employed and pa...

Page 91: ...are accomplished is left to individual software designers The Open Systems Interconnect OSI seven layer model has been adopted as the reference for the description of modern networking including the I...

Page 92: ...yering as simply a tool for visualizing the organization of the necessary software and hardware in a network In this view Layer 2 represents switching and Layer 3 represents routing Protocol layering...

Page 93: ...fferent ways As long as peers can communicate and interoperate this has no impact on the functioning of the network The communication between layers within a given protocol stack can be both different...

Page 94: ...3 functions IP is the premier Layer 3 protocol IP is itself only one protocol in the IP protocol suite More extensive capabilities are found in the other protocols of the IP suite For example the Dom...

Page 95: ...y the lower layers UDP does not Layer 7 This layer known as the application layer provides access to either the end user application software such as a database Users communicate with the application...

Page 96: ...eassembled in the correct order Because these functions are required by a large number of applications they are grouped into a single protocol rather than being the part of the specifications for just...

Page 97: ...re envelope into it s own larger envelope This process is referred to as encapsulation Many levels of encapsulation are required for a packet to cross the Internet Packet Headers TCP Most data transmi...

Page 98: ...a packet is received uncorrupted TCP adds the binary value of all the octets in the packet and writes the sum in the checksum field The receiving TCP recalculates the checksum and if the numbers are d...

Page 99: ...r in the window field In practice a single packet can acknowledge the receipt of data and give permission for more data to be sent IP TCP sends its packets to IP with the source and destination IP add...

Page 100: ...er of gateways the packet is allowed to cross between the source and destination This number is decremented by one when the packet crosses a gateway and when the TTL reaches zero the packet is dropped...

Page 101: ...when the packet is received the checksum is recalculated If the two checksums are different the packet is dropped Figure 5 12 Ethernet Packet Header When a packet is received the headers are removed T...

Page 102: ...gned to applications that wait for requests These port numbers are referred to as well known ports TCP will open a connection to the FTP server using some random port number 1234 for example on the lo...

Page 103: ...the FTP sending commands to send a particular file Once the commands are sent a second connection is opened for the actual data transfer Although it is possible to send data on the same connection it...

Page 104: ...e packets and subsequent reassembly UDP does not keep track of what is sent UDP uses port numbers in a way that is directly analogous to TCP There are well known UDP port numbers for servers that use...

Page 105: ...The DNS servers are identified by IP addresses Mapping Domain Names to Addresses Name to address translation is performed by a program called a Name server The client program is called a Name resolve...

Page 106: ...if the DNS server cannot supply an answer it returns the address of the next DNS server the client should contact Each client must be able to contact at least one DNS server and each DNS server must...

Page 107: ...CP IP configuration and reinitialize When a new TCP IP configuration is received from a DHCP server the network device checks for a possible IP address conflict by sending an Address Resolution Protoc...

Page 108: ...s is on the local network If it is the packet can be sent directly to the remote device If it is not the local computer looks for the network address of the destination and the corresponding gateway a...

Page 109: ...maximum packet size across all of the networks that may make up the route for a connection IP has therefore a method to divide packets into multiple smaller packets to cross such networks This divisio...

Page 110: ...ved by a local computer First the local computer is the target of the request If it is the local ARP replies by sending its MAC IP address pair back to the requesting system Second if the local comput...

Page 111: ...e other low level topology discovery and maintenance protocols Figure 5 14 Class D Multicast Address Some of the reserved IP multicast addresses are as follows Address Assignment 224 0 0 0 Base Addres...

Page 112: ...ternet Group Management Protocol IGMP End users that want to receive multicast packets must be able to inform nearby routers that they want to become a multicast group member of the group these packet...

Page 113: ...cast packets from this source If there is one member the packet is forwarded If there are no members the packet is dropped IGMP Versions 1 and 2 Users that want to receive multicast packets need to be...

Page 114: ...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 t...

Page 115: ...thm is not a program An algorithm is a statement of how a problem can be solved A program is written to implement an algorithm Multicast packets are delivered by constructing multicast trees where the...

Page 116: ...simple algorithm Flooding duplicates a lot of packets and uses a lot of network bandwidth A multicast router must also keep a record of the multicast packets it has received for a period of time to de...

Page 117: ...a local router can determine if the path from the source through the local router to an immediately neighboring router If it is not the packet will be dropped at the next router and the packet should...

Page 118: ...s router This will remove the leaf router s branch from the spanning tree and no more multicast packets from that source will be forwarded to it Prune messages have a TTL equal to one so they can be s...

Page 119: ...M algorithm to construct its multicast delivery trees The first multicast packet received by a multicast router using DVMRP is flooded to all interfaces except the one on which the packet was received...

Page 120: ...hich is used when the multicast destinations are closely spaced and Protocol Independent Multicast Sparse Mode PIM SM which is used when the multicast destinations are spaced further apart PIM DM is m...

Page 121: ...A router will not replace a route with a newly learned one if the new route has the same hop count sometimes referred to as cost So learned routes are retained until a new route with a lower hop count...

Page 122: ...of forming transient routing loops Hold down can be used to force a router to ignore new route updates for a period of time usually 60 seconds after a new route update has been received This allows a...

Page 123: ...DES 3326S Layer 3 Fast Ethernet Switch User s Guide Switch Management and Operating Concepts 123 Figure 5 17 RIP v 1 Message Format...

Page 124: ...9 Update Request 10 Update Response 11 Update Acknowledgement Table 5 15 RIP Command Codes The field VERSION contains the protocol version number 1 in this case and is used by the receiver to verify w...

Page 125: ...ersion 1 cannot be used to propagate classless addresses Routers running RIP version 1 must send different update messages for each IP interface to which it is connected Interfaces that use the same s...

Page 126: ...t can be used to identify the origin of the route Because the version number in RIP2 occupies the same octet as in RIP1 both versions of the protocols can be used on a given router simultaneously with...

Page 127: ...change to this database on one router triggers an update to the link state database of all other routers in that area Routers that have interfaces connected to more than one area are called Border Rou...

Page 128: ...h Tree to all destinations with the individual router as the root The IP routing table will then be made up of the destination address associated cost and the address of the next hop to reach each des...

Page 129: ...sely proportional to the bandwidth of the interface i e a higher bandwidth interface has a lower cost There is then a higher cost and longer time delays in sending packets over a 56 Kbps dial up conne...

Page 130: ...DES 3326S Layer 3 Fast Ethernet Switch User s Guide 130 Switch Management and Operating Concepts Figure 5 19 Constructing a Shortest Path Tree...

Page 131: ...s the network from the viewpoint of Router A Router A can reach 192 213 11 0 through Router B with a cost of 10 5 15 Router A can reach 222 211 10 0 through Router C with a cost of 10 10 20 Router A c...

Page 132: ...g Router A s shortest path tree but is very important when Router B is constructing its shortest path tree Note also that directly connected networks are reached at a cost of 0 while other networks ar...

Page 133: ...ecessary routing information and changes between areas Areas are specific to the router interface A router that has all of its interfaces in the same area is called an Internal Router A router that ha...

Page 134: ...outing information about other networks within the AS Normally all Summary link state updates are forwarded to the backbone area 0 and are then forwarded to all other areas in the network Border Route...

Page 135: ...nalyzer is used to obtain the password Message Digest Authentication MD 5 MD 5 authentication is a cryptographic method A key and a key ID are configured on each router The router then uses an algorit...

Page 136: ...there is a discontinuity in area 0 Areas Not Physically Connected to Area 0 All areas of an OSPF network should have a physical connection to the backbone but is some cases it is not possible to phys...

Page 137: ...lowing conditions before the become neighbors Area ID two routers having a common segment their interfaces have to belong to the same area on that segment Of course the interfaces should belong to the...

Page 138: ...er DR and a second router as the Backup Designated Router BDR on each multi access segment the BDR is a backup in case of a DR failure All other routers on the segment will then contact the DR for lin...

Page 139: ...as been established The router has seen its address in the Hello packets coming from a neighbor At the end of this stage the DR and BDR election would have been done At the end of the Two way stage ro...

Page 140: ...ate database Adjacencies on Point to Point Interfaces OSPF Routers that are linked using point to point interfaces such as serial links will always form adjacencies The concepts of DR and BDR are unne...

Page 141: ...router to determine if the packet should be accepted for further processing The format of the OSPP packet header is shown below OSPF Packet Header Type Router ID Area ID Checksum Au Authentication Au...

Page 142: ...r ID of the packet s source Area ID A 32 bit number identifying the area that this packet belongs to All OSPF packets are associated with a single area Packets traversing a virtual link are assigned t...

Page 143: ...on those physical networks having a multicast or broadcast capability enabling dynamic discovery of neighboring routers All routers connected to a common network must agree on certain parameters such...

Page 144: ...o Router Dead Interval Designated Router Backup Designated Rout Neighbor Packet Length entication Type ns Router Priority er Figure 5 23 Hello Packet Field Description Network Mask The network mask as...

Page 145: ...s down Designated Router The identity of the DR for this network in the view of the advertising router The DR is identified here by its IP interface address on the network Backup Designated Router The...

Page 146: ...One of the routers is designated to be master the other a slave The master seconds Database Description packets polls which are acknowledged by Database Description packets sent by the slave response...

Page 147: ...that the router is the master during the Database Exchange process A zero indicates the opposite DD Sequence Number User to sequence the collection of Database Description Packets The initial value in...

Page 148: ...ets may need to be used The sending of Link State Request packets is the last step in bringing up an adjacency A router that sends a Link State Request packet has in mind the precise instance of the d...

Page 149: ...packets implement the flooding of link state advertisements Each Link State Update packet carries a collection of link state advertisements one hop further from its origin Several link state advertise...

Page 150: ...nt header Otherwise the format of each of the five types of link state advertisements is different The Link State Acknowledgment Packet Link State Acknowledgment packets are OSPF packet type 5 To make...

Page 151: ...ntication Checksum Link State Acknowledgment P 5 Link State Advertisement cket Length thentication Type acket Header Figure 5 27 Link State Acknowledgement Packet Each acknowledged link state advertis...

Page 152: ...ot This yields a routing table There are four types of link state advertisements each using a common link state header These are Router Links Advertisements Network Links Advertisements Summary Link A...

Page 153: ...er Length Figure 5 28 Link State Advertisement Header Field Description Link State Age The time is seconds since the link state advertisement was originated Options The optional capabilities supporte...

Page 154: ...advertisement s Link State Type Advertising Router The Router ID of the router that originated the Link State Advertisement For example in network links advertisements this field is set to the Router...

Page 155: ...tate advertisement header Table 5 19 Link State Advertisement Header Router Links Advertisements Router links advertisements are type 1 link state advertisements Each router in an area originates a ro...

Page 156: ...S TOS TOS Link ID Link Data 0 0 V B E ns Link State Type ber Length ts umber of Links TOS 0 Metric Metric Metric Figure 5 29 Routers Links Advertisement In router links advertisements the Link State I...

Page 157: ...y this advertisement This must be the total collection of router links to the area Table 5 20 Routers Links Advertisement The following fields are used to describe each router link Each router link is...

Page 158: ...sit network 3 Connection to a stub network 4 Virtual link Link ID Identifies the object that this router link connects to Value depends on the link s Type When connecting to an object that also origin...

Page 159: ...s it specifies the network s IP address mask For unnumbered point to point connection it specifies the interface s MIB II ifIndex value For other link types it specifies the router s associated IP int...

Page 160: ...ics must be listed in order of increasing TOS encoding For example the metric for TOS 16 must always follow the metric for TOS 8 when both are specified Field Description TOS IP Type of Service that t...

Page 161: ...why the TOS and metric fields need not be specified in the network links advertisement The format of the Network Links Advertisement is shown below Link State Age Optio Link State ID Advertising Route...

Page 162: ...ter that belongs to the Autonomous System AS yet is outside the area Type 3 link state advertisements are used when the destination is an IP network In this case the advertisement s Link State ID fiel...

Page 163: ...d for each IP Type of Service Note that the cost for TOS 0 must be included and is always listed first If the T bit is reset in the advertisement s Option field only a route for TOS 0 is described by...

Page 164: ...h destination known to the router that is external to the AS AS external link advertisements usually describe a particular external destination For these advertisements the Link State ID field specifi...

Page 165: ...External Route Tag E ns ber Length ents 5 Figure 5 32 AS External Link Advertisement Field Description Network Mask The IP address mask for the advertised destination E bit The type of external metri...

Page 166: ...s set to 0 0 0 0 data traffic will be forwarded instead to the advertisement s originator TOS The Type of Service that the following cost is relevant to Metric The cost of this route The interpretatio...

Page 167: ...crosoft Internet Explorer The Web browser acts as a universal access tool and can communicate directly with the Switch using the HTTP protocol The Web based management module and the Console program a...

Page 168: ...rich feature set requires a bit of thought to arrive at a deployment strategy that will maximize the potential of the DES 3326S Layer 3 switch General Deployment Strategy 1 Determine how the network w...

Page 169: ...e A policy is a mechanism to alter the normal packet forwarding in a network device and can be used to intelligently allocate bandwidth to time critical applications such as the integration of voice v...

Page 170: ...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 to accommodate the IP subnets Finally the...

Page 171: ...ple Netscape Navigator or Microsoft Internet Explorer Follow the installation instructions for the browser The second and last step is to configure the IP interface of the Switch This can be done manu...

Page 172: ...Login Button This opens the management module s main page The switch management features available in the web based are explained below Configuring the Switch User Accounts Management From the Main Me...

Page 173: ...an initial password and then confirm the new password Determine whether the new user should have Root User or User privileges 2 Click on APPLY to make the user addition effective 3 A listing of all u...

Page 174: ...es must be entered into non volatile ram using the Save Changes command on the Main Menu if you want these changes to be permanent Admin and User Privileges There are two levels of user privileges Adm...

Page 175: ...eset Yes No Reboot Switch Yes No User Account Management Add Update Delete User Accounts Yes No View User Accounts Yes No Table 6 1 Root User and User Privileges After establishing a User Account with...

Page 176: ...arting 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 config...

Page 177: ...ey become the default settings for the switch These settings will be used every time the switch is rebooted Factory Reset The following menu is used to restart the switch using only the configuration...

Page 178: ...ts current IP address Click No to reset the switch s IP address to the factory default 10 90 90 90 with a Subnet Mask of 255 0 0 0 and Default Gateway 0 0 0 0 Click the Apply button to restart the swi...

Page 179: ...which is accessible via either the serial console or Telnet Refer to the User Guide that came with your system for more information subsection describe the required configuration Setting an IP Addres...

Page 180: ...the switch can be assigned an IP address and subnet mask which can then be used to connect a management station to the switch s web based management agent Saving Configuration Changes Clicking the App...

Page 181: ...eb based manager 1 Start a Java enabled Web browser from any machine with network access to the switch Preferred browsers include Internet Explorer 4 0 or above or Netscape Navigator 4 0 or above 2 En...

Page 182: ...2 The full application will now launch A three frame page will display with a switch graphic located in the upper right hand frame 3 To stop the web based manager simply close the Web browser applica...

Page 183: ...s Guide Web Based Switch Management 183 Areas of the User Interface The figure below shows the user interface The user interface is divided into 3 distinct areas as described in the table Area 1 Area...

Page 184: ...he 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 functio...

Page 185: ...the DES 3326Ss switch using the Web based Manager you can perform any of the tasks described in the following sections Setting Up The Switch Basic Setup This section will help prepare the Switch user...

Page 186: ...DES 3326S Layer 3 Fast Ethernet Switch User s Guide 186 Web Based Switch Management Figure 6 10 Switch Information Basic Settings...

Page 187: ...at the person responsible for the maintenance of the network system that this Layer 3 switch is installed on be listed here IP Address Configuring the Switch s IP Address The Switch needs to have an I...

Page 188: ...DES 3326S Layer 3 Fast Ethernet Switch User s Guide 188 Web Based Switch Management Figure 6 11 Basic Switch Setup...

Page 189: ...ddress in this field If no VLANs have been previously configured on the switch you can use the default VLAN named default The default VLAN contains all of the switch ports as members If VLANs have bee...

Page 190: ...look for a DHCP server to provide it with this information before using the default or previously entered settings Manual Allows the entry of an IP address Subnet Mask and a Default Gateway for the sw...

Page 191: ...accessible outside your local network you can leave this field unchanged VLAN Name This allows the entry of a VLAN name from which a management station a computer will be allowed to manage the switch...

Page 192: ...ck the Management Station IP link in the Management menu The following screen appears Figure 6 12 Management Station IP Settings Management stations are computers on the network that will be used to m...

Page 193: ...management host A community sting is an alphanumeric string of up to 32 characters used to authentication of users wanting access to the switch s SNMP agent Read read only allows the user using the a...

Page 194: ...gure 6 13 SNMP Community Setup Setting Up Trap Receivers This allows the switch to send traps messages about errors etc to management stations on the network Click the SNMP Trap Recipients link in the...

Page 195: ...ilar to a password in that stations that do not know the correct string cannot receive or request SNMP information from the switch The Status field can be toggled between Enabled and Disabled to enabl...

Page 196: ...6 15 Switch Stack Display In this case there are two switches in the switch stack The Unit 1 master switch is on top and highlighted in blue The Unit 2 slave switch is below and not highlighted To se...

Page 197: ...dress of the switch assigned by the factory The Start Port field displays the first port assigned to the corresponding switch in the switch stack The Port Range field displays the total number of port...

Page 198: ...number The stacking order can be automatically configured using the switch s MAC address the lower the numerical value of a given switch s MAC address the lower the number in the stacking order the sw...

Page 199: ...layed in the console as is displayed in the Web based management agent The config stack command allows you to configure the switch stack manually The syntax of the config stacking command is as follow...

Page 200: ...their unit numbers are determined by the numerical value of their respective MAC addresses standalone This command effectively removes the switch connected to the management station via the switch s...

Page 201: ...u will have to move the management stations s console connection via the serial port to the switch with MAC address 00 11 33 44 55 60 and enter the following command config stacking mode master This w...

Page 202: ...DES 3326S Layer 3 Fast Ethernet Switch User s Guide 202 Web Based Switch Management Configure Ports Click the Port Configurations link from the Basic Setup folder Figure 6 21 Port Configurations...

Page 203: ...is will open the following dialog box Figure 6 22 Port Configurations Edit The Unit drop down dialog box allows you to select different switches in a switch stack if you have the optional stacking mod...

Page 204: ...Port s MAC Address Learning A given port s or a range of port s dynamic MAC address learning can be locked such that the current source MAC addresses entered into the MAC address forwarding table can...

Page 205: ...heme used for the various port configurations Ports configured for full duplex use 802 3x flow control half duplex ports use backpressure flow control and Auto ports use an automatic selection of the...

Page 206: ...lect either the Console or the SLIP protocol The following fields can then be set Console Settings Parameter Description Baud Rate Displays the serial bit rate used to communicate with a management st...

Page 207: ...bits Stop Bits Displays the number of bits used to indicate that a word has been completely transmitted The console interface uses 1 stop bit Auto Logout This sets the time the interface can be idle...

Page 208: ...en the switch s operating mode is changed Configuring VLANs The switch allows the assignment of an IP interface to each VLAN in IP Routing mode The VLANs must be configured prior to setting up the IP...

Page 209: ...Figure 6 24 802 1Q VLANs To delete an existing 802 1Q VLAN click the corresponding click box to the left of the VLAN you want to delete from the switch and then click the Delete button To create a new...

Page 210: ...y Settings Edit The following fields can then be set in either the Add or Edit dialog boxes Parameter Description VLAN ID VID Allows the entry of a VLAN ID in the Add dialog box or displays the VLAN I...

Page 211: ...header is changed to include the 32 bit tag associated with the VID VLAN Identifier see below When a tagged packet exits the port the packet header is unchanged Untagged Allows an individual port to b...

Page 212: ...VLAN dynamically The Port VLAN ID PVID dialog box shown below allows you to determine whether the switch will share its VLAN configuration information with other Group VLAN Registration Protocol GVRP...

Page 213: ...ID 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 GVRP Disabl...

Page 214: ...To enable or disable GVRP globally on the switch Go to the VLAN Configurations link and click on the Switch GVRP link Figure 6 28 Switch GVRP Parameter Description GVRP disabled Group VLAN Registrati...

Page 215: ...AN s corresponding IP interface An example is presented below VLAN Name VID Switch Ports System default 1 5 6 7 8 21 22 23 24 Engineer 2 9 10 11 12 Marketing 3 13 14 15 16 Finance 4 17 18 19 20 Sales...

Page 216: ...ress VLAN Name VID Network Number IP Address System default 1 10 32 0 0 10 32 0 1 Engineer 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 1...

Page 217: ...et Switch User s Guide Web Based Switch Management 217 Figure 6 29 Setup IP Interface To setup an new IP interface click the New button Figure 6 30 Setup IP Interface Add To edit an existing IP interf...

Page 218: ...bove Enter the interface s IP address and subnet mask in the corresponding fields Pull the Active pull down menu to Yes and click Apply to enter to make the IP interface effective Use the Save Changes...

Page 219: ...bar This entry determines whether the interface will be active or not Switch This drop down menu allows the selection of an individual switch from a switch stack if you have the optional stacking mod...

Page 220: ...This window allows RIP to be globally enabled and disabled on the switch without changing the RIP configuration To configure RIP on the switch highlight Setup RIP from the RIP Settings folder under t...

Page 221: ...ng fields can be set Parameter Description Interface Name The name of the IP interface on which RIP is to be setup This interface must be previously configured on the Switch TX Mode Disabled Toggle am...

Page 222: ...fy that routers on the network should us the Password above to authenticate router table exchanges OSPF MD5 Key Table Configuration The MD5 Key Table Configuration menu allows the entry of a 16 charac...

Page 223: ...ble The following fields can be set Parameter Description Key ID A number from 1 to 255 used to identify the MD5 Key Key A alphanumeric string of between 1 and 16 case sensitive characters used to gen...

Page 224: ...nated as an Autonomous System AS Border Router or not From the Layer 3 IP Networking folder click on the OSPF folder and then click on the General link Figure 6 36 Setup OSPF The following parameters...

Page 225: ...Border Router Autonomous System Border Router determines whether or not the switch is configured as an AS Border Router State Allows OSPF to be enabled or disabled globally on the switch without chan...

Page 226: ...ntifies the OSPF area in the OSPF domain Type This field can be toggled between Normal and Stub using the space bar When it is toggled to Stub additional fields appear Stub Import Summary LSA and Stub...

Page 227: ...a from the list OSPF Interface Configuration To configure an OSPF Interface click on the OSPF Interface Configuration link Figure 6 38 OSPF Interface Configuration All of the IP Interfaces currently c...

Page 228: ...interface previously configured on the switch Area ID Allows the entry of an OSPF Area ID configured above Router Priority Allows the entry of a number between 0 and 255 representing the OSPF priorit...

Page 229: ...ied The Dead Interval must be evenly divisable by the Hello Interval State Allows the OSPF interface to be disabled for the selected area without changing the configuration for that area Auth Type Thi...

Page 230: ...st be the same MD5 Key as used by the neighboring router Metric This field allows the entry of a number between 1 and 65 535 that is representative of the OSPF cost of reaching the selected OSPF inter...

Page 231: ...ave a physical connection to the backbone also called Area 0 or to link areas of the backbone itself that are discontinuous This allows routing information to flow from an area that is physically disc...

Page 232: ...Area ID previously defined on the switch that allows a remote area to communicate with the backbone area 0 A Transit Area cannot be a Stub Area or a Backbone Area Neighbor Router The OSPF router ID f...

Page 233: ...tion in the volume of LSDB advertisement traffic as well as a reduction in the memory overhead in the switch used to maintain routing tables To configure OSPF Area Aggregation on the switch click the...

Page 234: ...on the network that are running different routing protocols to exchange routing information This is accomplished by comparing the routes stored in the various router s routing tables and assigning ap...

Page 235: ...rotocol Allows the selection of the protocol of the destination device Available choices are RIP and OSPF Metric Type Allows the selection of one of two methods for calculating the metric value Type 1...

Page 236: ...DES 3326S Layer 3 Fast Ethernet Switch User s Guide 236 Web Based Switch Management Count in the RIP routing protocol...

Page 237: ...folder IGMP Snooping DVMRP and PIM DM can be enabled or disabled on the switch without changing the individual protocol s configuration To enable or disable IGMP Snooping DVMRP and PIM DM globally on...

Page 238: ...window IGMP Snooping Settings To configure IGMP Snooping From the Layer 3 IP Networking folder select the IP Multicast Routing Protocols folder and click IGMP Snooping Configurations to open the follo...

Page 239: ...of time allowed before sending an IGMP response report A value between 1 and 25 seconds can be entered with a default of 10 seconds Robustness Var A tuning variable to allow for sub networks that are...

Page 240: ...nfigured on the switch on a per IP interface basis Each IP interface configured on the switch is displayed in the above IGMP Interface Configuration dialog box To configure IGMP for a particular inter...

Page 241: ...se Time field The Robustness Variable field allows IGMP to be tuned for sub networks that are expected to lose a lot of packets A high value max 255 for the robustness variable will help compensate fo...

Page 242: ...entered with a default of 10 seconds Robustness Variable 2 A tuning variable to allow for subnetworks that are expected to lose a large number of packets A value between 2 and 255 can be entered with...

Page 243: ...s are pruned and shortest path DVMRP is relatively efficient Because multicast group membership information is forwarded by a distance vector algorithm propagation is slow DVMRP is optimized for high...

Page 244: ...oute cost is a relative number that is used by DVMRP to calculate which branches of a multicast delivery tree should be pruned The cost is relative to other costs assigned to other DVMRP routes throug...

Page 245: ...ree It is similar to but not defined as the hop count in RIP The default cost is 1 State Disabled This field can be toggled between Enabled and Disabled and enables or disables DVMRP for the IP interf...

Page 246: ...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 multicast messages...

Page 247: ...ing fields can be set Parameter Description Interface Name Allows the entry of the name of the IP interface for which PIM DM is to be configured This must be a previously defined IP interface IP Addre...

Page 248: ...tween Enabled and Disabled using the pull down menu and is used to enable or disable PIM DM for the IP interface The default is Disabled Static Router Port Settings A static router port is a port that...

Page 249: ...packets were all forwarded to the router port A router port will be dynamically configured when IGMP query packets RIPv2 multicast DVMRP multicast PIM DM multicast packets are detected flowing into a...

Page 250: ...n click the Edit button to open the following dialog box Figure 6 53 Static Router Port Settings Add The following fields can be set Parameter Description VLAN Name Displays the name of the VLAN the s...

Page 251: ...port where 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 Up t...

Page 252: ...ption Source Port Allows the entry of the port number of the port to be mirrored This port is the source of the packets to be duplicated and forwarded to the Target port Direction Ingress This field c...

Page 253: ...sed Switch Management 253 Priority To configure a forwarding priority for a given MAC address Click the Priority link on the Configuration menu Figure 6 55 Setup MAC Address Priority To add a MAC Addr...

Page 254: ...Management Figure 6 56 MAC Address Priority Add To edit the priority configuration for a given MAC Address entry to the MAC Address Priority table click the corresponding click box for the MAC Addres...

Page 255: ...the entry of the VLAN Name the MAC address above is a member of When editing and existing entry displays the name of the VLAN to which the MAC address above is a member of User Priority 0 This field c...

Page 256: ...to Layer 3 Operation mode both MAC and IP addresses can be entered into the filtering table using their respective entry menus To enter an address open Configuration select Filtering choose MAC Filter...

Page 257: ...it an existing IP address entry in the filtering table click the Edit button Figure 6 60 IP Address Filtering Edit The following fields can be set Parameter Description IP Address 0 0 0 0 Allows the e...

Page 258: ...d between Source Destination and Either The IP address entered into the filtering table can be filtered as a source packets will not be received from the IP address as a destination packets will not b...

Page 259: ...ddress will remain in the forwarding table without being accessed 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 secon...

Page 260: ...witch s MAC Address Forwarding Table These addresses will never age out To enter a MAC address into the switch s forwarding table click on the Forwarding folder and then the MAC Forwarding folder and...

Page 261: ...ddress Settings Add To edit an existing entry in the MAC address in the MAC Address Forwarding Table click the Edit button Figure 6 64 Unicast MAC Address Settings Edit The following fields can be set...

Page 262: ...xisting entry Unit Allows the selection of a given switch from a switch stack if you have the optional stacking module installed and have properly interconnected the switches in a switch stack Port Al...

Page 263: ...ulticast MAC Address Settings To add a new multicast MAC address to the switch s forwarding table click the New button Figure 6 66 Multicast MAC Address Settings Add To edit an existing entry to the s...

Page 264: ...static forwarding table VLAN Name Allows the entry of the VLAN name of the VLAN the MAC address below is a member of when adding a new entry to the table Displays the VLAN name of the VLAN the MAC add...

Page 265: ...dynamically IP Forwarding Entries 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 an IP address into the s...

Page 266: ...a new static default route click the New button Figure 6 69 Static Default Routes Add The following fields can be set Parameter Description IP Address 0 0 0 0 Allows the entry of an IP address that w...

Page 267: ...otocol metric representing the number of routers between the switch and the IP address above Static ARP To make a static ARP entry click the IP Forwarding folder and then the Static ARP link Figure 6...

Page 268: ...arameter Description IP Address The IP address of the ARP entry MAC Address The MAC address of the ARP entry Spanning Tree STP Switch Settings The Spanning Tree Protocol STP operates on two levels on...

Page 269: ...tch Settings link Figure 6 72 STP Switch Settings The factory default setting should cover the majority of installations It is advisable to keep the default settings as set at the factory unless it is...

Page 270: ...llo Time 1 10 sec 2 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 t...

Page 271: ...ameters Max Age 2 x Forward Delay 1 second Max Age 2 x Hello Time 1 second STP Port Settings The Spanning Tree Protocol STP operates on two levels on the switch level the settings are globally impleme...

Page 272: ...DES 3326S Layer 3 Fast Ethernet Switch User s Guide 272 Web Based Switch Management Figure 6 73 STP Port Settings...

Page 273: ...oot port is a port of the group that is elected on the basis of port priority and port cost to be the connection to the network for the group Redundant links will be blocked just as redundant links ar...

Page 274: ...p may not contain ports 8 and 9 for example and all of the ports in the group must be members of the same VLAN Further the aggregated links must all be of the same speed and should be configured as fu...

Page 275: ...switch STP will block one entire group in the same way STP will block a single port that has a redundant link To configure a link aggregation group click on the Link Aggregation link from the Advanced...

Page 276: ...e following fields can be set Parameter Description Group ID Allows the entry of a number used to identify the link aggregation group when adding a new group Displays the Group ID of the currently sel...

Page 277: ...ive network device or to have an absolute backup link aggregation group that is not under automatic control Utilities TFTP Utilities Trivial File Transfer Protocol TFTP services allow the switch firmw...

Page 278: ...stacking module and have properly interconnected the switches Enter the IP address of the TFTP server in the Server IP Address field The TFTP server must be on the same IP subnet as the switch Enter t...

Page 279: ...itch s click on the Basic Setup folder and then the Switch Utilities folder and then the TFTP Services folder and finally click on the Download Configuration from TFTP Server link Figure 6 78 Use Conf...

Page 280: ...pload Settings to TFTP Server link Figure 6 79 Save Settings To TFTP Server Enter the IP address of the TFTP server and the path and filename of the settings file on the TFTP server and click Apply Hi...

Page 281: ...Start to initiate the file transfer Utilities BOOTP DHCP Relay BOOTP DHCP Relay can be configured on both the switch level or on a per IP interface level The BOOTP DHCP Relay link allows for switch le...

Page 282: ...menu It is used to enable or disable the BOOTP DHCP Relay service on the switch The default is Disabled BOOTP HOPS Count Limit 4 This field allows an entry between 1 and 16 to define the maximum numbe...

Page 283: ...ntered the switch will use that value along with the hop count to determine whether to forward a given BOOTP or DHCP packet To configure the BOOTP DHCP Relay interface click on the BOOTP DHCP Relay In...

Page 284: ...be set Parameter Description Interface Name The interface name of the IP interface on which the BOOTP or DHCP servers reside on BOOTP DHCP Server 0 0 0 0 Allows the entry of IP addresses for up to fo...

Page 285: ...ddress of a primary domain name server DNS Name Server 2 0 0 0 0 Allows the entry of the IP address of a secondary domain name server DNS DNSR Relay Cache Server Status Disabled This can be toggled be...

Page 286: ...Static Table Configuration To add a new entry to the table click on the New button Figure 6 86 DNS Relay Static Table Configuration Add The following fields can be set Parameter Description Domain Nam...

Page 287: ...hich operating mode the switch is in Layer 2 network monitoring functions are visible on the console when the switch is in Layer 2 Only operating mode Layer 3 network monitoring functions are added to...

Page 288: ...itch User s Guide 288 Web Based Switch Management Figure 6 87 Port Utilization window Select the desired port by clicking on the front panel display The Update Interval field sets the interval at whic...

Page 289: ...uspend The time between updates received from the switch in seconds Suspend stops the updates The default is Suspend Port Error Statistics The Port Error Packet Statistics window displays the packet e...

Page 290: ...The Update Interval field sets the interval at which the error statistics are updated The following fields from above are described in more detail Parameter Description Unit Allows the selection of a...

Page 291: ...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 longe...

Page 292: ...or alignment errors For 100 Mbps ports the counter records the sum of CRC errors and code errors frames received with rxerror signal Late Collision Late Collisions The number of times that a collision...

Page 293: ...ed or transmitted by a given switch port In addition statistics on the number and rate of unicast multicast and broadcast packets received by the switch are displayed To view an analysis of packets re...

Page 294: ...per second by the switch Unicast RX Displays the number of unicast packets received by the switch in total number Frames and the rate Frames sec Multicast RX Displays the number of multicast packets...

Page 295: ...transmitted by the switch in total number Total and rate Total sec MAC Address Table This allows the switch s dynamic MAC address forwarding table to be viewed When the switch learns an association b...

Page 296: ...3 Fast Ethernet Switch User s Guide 296 Web Based Switch Management Figure 6 90 Browse Address Table sequential window IP Address Table To view the contents of the IP Routing table click on the IP Add...

Page 297: ...DES 3326S Layer 3 Fast Ethernet Switch User s Guide Web Based Switch Management 297...

Page 298: ...DES 3326S Layer 3 Fast Ethernet Switch User s Guide 298 Web Based Switch Management Figure 6 91 IP Address Table...

Page 299: ...Gateway Displays the default or next hop gateway to reach the destination Jump Click the Jump button to go to a particular combination of destination IP address subnet mask and gateway address Interfa...

Page 300: ...IP address of the router Netmask The subnet mask corresponding to the IP address above Gateway The IP address of the gateway between the switch and this router Interface Name The name of the IP interf...

Page 301: ...DES 3326S Layer 3 Fast Ethernet Switch User s Guide Web Based Switch Management 301 ARP Table To view the switch s ARP table click on the ARP Table link...

Page 302: ...DES 3326S Layer 3 Fast Ethernet Switch User s Guide 302 Web Based Switch Management Figure 6 93 ARP Table...

Page 303: ...Antonymous Systems AS The External LSDB describes the LSAa for those ASs not belonging to OSPF The internal OSPF Link State Database LSDB table can be viewed using the Web based manager To view the s...

Page 304: ...tate ID This field identifies the portion of the internet environment that is being described by the advertisement The contents of this field depend on the advertisement s LS type LS Type Link State I...

Page 305: ...ring router IP Address The IP address of the neighboring router Neighbor Options This field indicates whether the neighbor router can accept OSPF optional operation within its OSPF domain For example...

Page 306: ...virtual link resides on Virtual Neighbor ID The router ID of the neighboring router via the virtual link IP Address The IP address of the neighboring router Virtual Neighbor Options This field indica...

Page 307: ...e entry of an IP address and corresponding subnet mask to search the table for Click Jump and the DVMRP Routing table will be searched for the IP address and subnet mask above The following fields are...

Page 308: ...e Name The name of the IP interface the router resides on Expire The total number of routers that the packets can cross GVRP Status This allows the GVRP status for each of the switch s ports to be vie...

Page 309: ...d as a static router port designated by S A router port that is dynamically configured by the switch is designated by D To view the Router Port table click on the Router Ports link Figure 6 99 Browse...

Page 310: ...ified with an M The number of IGMP reports that were snooped is also displayed in the Reports field To view the IGMP Snooping table click on the IGMP Snooping Status link Figure 6 100 IGMP Snooping Ta...

Page 311: ...gure 6 101 IP Multicast Forwarding Table Parameter Description Multicast Group The IP address of the multicast group Source IP Address The IP address of the multicast source Source Mask The subnet mas...

Page 312: ...Group Table To view the switch s IGMP group table click on the IGMP Group Table link Figure 6 102 IGMP Group Table Parameter Description Interface Name The name of the IP interface the IGMP Group res...

Page 313: ...RP Routing Table To view the switch s DVMRP routing table click on the DVMRP Routing Table link Figure 6 103 DVMRP Routing Table Parameter Description Source Address The IP address of the DVMRP router...

Page 314: ...The name of the IP interface the router resides on Expire The total number of routers that the packets can cross Switch History This allows the Switch History Log to be viewed The switch records all t...

Page 315: ...DES 3326S Layer 3 Fast Ethernet Switch User s Guide Web Based Switch Management 315 Figure 6 104 Switch History...

Page 316: ...3u 100BASE TX Fast Ethernet IEEE 802 3z 1000BASE SX Gigabit Ethernet IEEE 802 3ab 1000BASE T Gigabit Ethernet IEEE 802 1 P Q VLAN IEEE 802 3x Full duplex Flow Control ANSI IEEE 802 3 Nway auto negotia...

Page 317: ...e Both types use MTRJ or SC optical connector Number of Ports 24 x 10 100 Mbps NWay ports 2 Gigabit Ethernet optional Physical and Environmental AC inputs 100 240 VAC 50 60 Hz internal universal power...

Page 318: ...Tick AS NZS3548 BSMI CNS 13438 Safety CSA International CE Mark CSA 60950 UL60950 IEC60950 EN60950 Performance Transmission Method Store and forward RAM Buffer 8 MB per device Filtering Address Table...

Page 319: ...s them to the switch s CPU BPDU packets from the CPU are processed If no BPDUs that suggest the port should go to the blocking state are received The port waits for the expiration of the forward delay...

Page 320: ...etwork is the best choice for the root switch If there is only one switch on the network no BPDU exchange occurs the forward delay timer expires and the ports move to the listening state All STP enabl...

Page 321: ...DES 3326S Layer 3 Fast Ethernet Switch User s Guide Understanding and Troubleshooting the Spanning Tree Protocol 321...

Page 322: ...rding state but should return to 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 liste...

Page 323: ...DES 3326S Layer 3 Fast Ethernet Switch User s Guide Understanding and Troubleshooting the Spanning Tree Protocol 323...

Page 324: ...e learning state from the listening state A port in the learning state does the following Discards frames received from the network segment to which it is attached Discards packets sent from another p...

Page 325: ...DES 3326S Layer 3 Fast Ethernet Switch User s Guide Understanding and Troubleshooting the Spanning Tree Protocol 325...

Page 326: ...m the learning state when the forward delay timer expires A port in the forwarding state does the following Forwards packets received from the network segment to which it is attached Forwards packets...

Page 327: ...DES 3326S Layer 3 Fast Ethernet Switch User s Guide Understanding and Troubleshooting the Spanning Tree Protocol 327...

Page 328: ...tate is virtually non operational A disabled port does the following Discards packets received from the network segment to which it is attached Discards packets sent from another port on the switch fo...

Page 329: ...DES 3326S Layer 3 Fast Ethernet Switch User s Guide Understanding and Troubleshooting the Spanning Tree Protocol 329...

Page 330: ...that should be in the blocking state but is forwarding packets In this example B has been elected as the designated bridge and port 2 on C is in the blocking state The election of B as the designated...

Page 331: ...f 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...

Page 332: ...en accessing the link B will then start sending packets even if A is using the link A will then detect collisions and begin to run the flow control algorithm If there is enough traffic between B and A...

Page 333: ...rt 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 prev...

Page 334: ...implemented in software and is thus reliant upon the speed of the CPU and other factors to converge If the CPU is over utilized it is possible that BPDUs may not be sent in a timely fashion STP is gen...

Page 335: ...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...

Page 336: ...N know which ports should be blocking in a stable network A network diagram that shows each physical loop in the network and which ports break which loops is extremely helpful Minimize the number of p...

Page 337: ...C and D have redundant links to the backbone switches A and B using trunks Trunks 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...

Page 338: ...e Protocol switches A and B and two blocked ports per VLAN This increases the chance of a data loop In this example the VLAN definitions are extended to switches A and B This gives only a single block...

Page 339: ...DES 3326S 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 correc...

Page 340: ...3 switches and IP routing eliminates 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 fas...

Page 341: ...DES 3326S Layer 3 Fast Ethernet Switch User s Guide Understanding and Troubleshooting the Spanning Tree Protocol 341...

Page 342: ...is 1 otherwise the result is 0 0 1 0 0 0 1 0 1 OR The logical OR operation 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 1 1 1 1 XOR The logic...

Page 343: ...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 This operation is carried out on a single bit 0 1 1 0...

Page 344: ...Age 62 261 Bridge Priority 62 Browse the Routing Table 288 C Configuration 178 Connections Switch to End Node 36 Switch to Hub or Switch 37 Console 34 console port 14 25 Console port RS 232 DCE 42 Con...

Page 345: ...erature 308 Out of Band Console Setting menu 197 P password 172 Port Priority 63 port based VLANs 68 ports 14 Power 34 Power Consumption 308 R RAM 168 RAM Buffer 309 Rear Panel 26 RS 232 14 S Saving C...

Page 346: ...Start 48 51 Link Change Event 49 51 New Root 48 Port Partition 51 Topology Change 48 51 Warm Start 48 51 Traps 47 50 trunk group 66 U Unpacking 20 untagging 68 Untagging 68 V VLAN 55 W web based manag...

Page 347: ...LINK GERMANY Bachstr 22 D 65830 Kriftel Germany TEL 49 0 6192 97110 FAX 49 0 6192 971111 WEB www dlink de BBS 49 0 6192 971199 Analog 49 0 6192 9711 98 ISDN INFO 00800 7250 0000 toll free HELP 00800 7...

Page 348: ...product 1 Where and how will the product primarily be used Home Office Travel Company Business Home Business Personal Use 2 How many employees work at installation site 1 employee 2 9 10 49 50 99 100...

Page 349: ......

Reviews: