3Com SuperStack 3C17300 Implementation Manual Download

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HAPTER

9: U

SING

UTOMATIC

IP C

ONFIGURATION

Important
Considerations

This section contains some important points to note when using the
automatic IP configuration feature.

The dynamic nature of automatically configured IP information means
that a Switch may change its IP address whilst in use.

Server Support

Your Switch has been tested to interoperate with DHCP and BOOTP
servers that use the following operating systems:

■

Microsoft Windows 2000 Server

■

Microsoft Windows NT4 Server

■

Sun Solaris v2.5.1

If you want DHCP or BOOTP to be the method for automatic
configuration, make sure that your DHCP or BOOTP servers are operating
normally before you power on your Switch.

Event Log Entries

and Traps

An event log will be generated and an SNMP trap will be sent if any of
the following changes occur in the IP configuration:

■

IP address configuration is changed manually

■

IP address changes from Auto-IP to DHCP IP configuration

■

DHCP negotiates a change in the IP configuration from Auto-IP

■

BOOTP negotiates a change in the IP configuration

Summary of Contents for SuperStack 3C17300

Page 1: ...ttp www 3com com Part No DUA1730 0BAA02 Published November 2002 SuperStack 3 Switch 4200 Series Implementation Guide Generic guide for units in the SuperStack 3 Switch 4200 Series 3C17300 3C17302 3C17304 ...

Page 2: ...portion of any legend provided on any licensed program or documentation contained in or delivered to you in conjunction with this User Guide Unless otherwise indicated 3Com registered trademarks are registered in the United States and may or may not be registered in other countries 3Com the 3Com logo and SuperStack are all registered trademarks of 3Com Corporation Intel and Pentium are registered ...

Page 3: ...ort Security 16 Aggregated Links 16 Auto negotiation 17 Multicast Filtering 17 Spanning Tree Protocol and Rapid Spanning Tree Protocol 18 Switch Database 18 Traffic Prioritization 18 RMON 19 Broadcast Storm Control 20 VLANs 20 2 OPTIMIZING BANDWIDTH Port Features 21 Duplex 21 Flow Control 22 Auto negotiation 22 Smart Auto sensing 23 Aggregated Links 24 How 802 3ad Link Aggregation Operates 24 Impl...

Page 4: ...STP Works 43 STP Requirements 43 STP Calculation 43 STP Configuration 44 STP Reconfiguration 44 How RSTP Differs to STP 45 STP Example 45 STP Configurations 46 Using STP on a Network with Multiple VLANs 48 5 USING THE SWITCH DATABASE What is the Switch Database 49 How Switch Database Entries Get Added 49 Switch Database Entry States 50 6 USING TRAFFIC PRIORITIZATION What is Traffic Prioritization ...

Page 5: ...AN 67 Communication Between VLANs 68 Creating New VLANs 68 VLANs Tagged and Untagged Membership 68 Placing a Port in a Single VLAN 69 VLAN Configuration Examples 70 Using Untagged Connections 70 Using 802 1Q Tagged Connections 71 9 USING AUTOMATIC IP CONFIGURATION How Your Switch Obtains IP Information 74 How Automatic IP Configuration Works 74 Automatic Process 75 Important Considerations 76 Serv...

Page 6: ...entation Switch Example 84 Desktop Switch Example 85 Advanced Network Configuration Examples 86 Improving the Resilience of Your Network 86 Enhancing the Performance of Your Network 87 C IP ADDRESSING IP Addresses 89 Simple Overview 89 Advanced Overview 90 Subnets and Subnet Masks 92 Default Gateways 94 GLOSSARY INDEX ...

Page 7: ...at are used to interconnect LANs For detailed descriptions of the web interface operations and the command line interface CLI commands that you require to manage the Switch please refer to the Management Interface Reference Guide supplied in HTML format on the CD ROM that accompanies your Switch If release notes are shipped with your product and the information there differs from the information i...

Page 8: ...ample To change your password use the following syntax system password password In this example you must supply a password for password Commands The word command means that you must enter the command exactly as shown and then press Return or Enter Commands appear in bold Example To display port information enter the following command bridge port detail The words enter and type When you see the wor...

Page 9: ...e CD ROM that accompanies your Switch Management Quick Reference Guide This guide contains A list of the features supported by the Switch A summary of the web interface operations and CLI commands that enable you to manage the Switch Release Notes These notes provide information about the current software release including new features modifications and known problems In addition there are other p...

Page 10: ...uide Part number DUA1730 0BAA0x Page 25 Please note that we can only respond to comments and questions about 3Com product documentation at this e mail address Questions related to technical support or sales should be directed in the first instance to your network supplier Product Registration You can now register your SuperStack 3 Switch on the 3Com web site http support 3com com registration fron...

Page 11: ...Bandwidth Chapter 3 Using Multicast Filtering Chapter 4 Using Resilience Features Chapter 5 Using the Switch Database Chapter 6 Using Traffic Prioritization Chapter 7 Status Monitoring and Statistics Chapter 8 Setting Up Virtual LANs Chapter 9 Using Automatic IP Configuration ...

Page 12: ...14 ...

Page 13: ...ge and monitor the way it works you have to access the management software that resides on the Switch This is known as managing the Switch Managing the Switch can help you to improve its efficiency and therefore the overall performance of your network There are several different methods of accessing the management software to manage the Switch These methods are explained in Chapter 3 of the Gettin...

Page 14: ... configuration feature works see Chapter 9 Using Automatic IP Configuration Port Security Port security guards against unauthorized users connecting devices to your network The port security feature Disconnect Unauthorised Device DUD disables a port if an unauthorised device transmits data on it Aggregated Links Aggregated links are connections that allow devices to communicate using up to four li...

Page 15: ...s during periods of congestion on the network Flow control is supported on ports operating in half duplex mode and is implemented using the IEEE 802 3x standard on ports operating in full duplex mode Smart Auto sensing Smart auto sensing allows auto negotiating multi speed ports such as 10 100 Mbps or 10 100 1000 Mbps to monitor and detect high error rates or problems in the physical interconnecti...

Page 16: ...fails RSTP is an enhanced version of the STP feature and is enabled by default RSTP can restore a network connection quicker than the STP feature RSTP can detect if it is connected to a legacy device that only supports IEEE 802 1D STP and will automatically downgrade to STP on that particular port STP conforms to the IEEE 802 1D 1998 standard and RSTP conforms to the IEEE 802 1w standard For more ...

Page 17: ...ture Quality of Service QoS enables you to specify service levels for different traffic classifications This enables you to prioritize particular applications or traffic types The Switch uses a policy based QoS mechanism By default all traffic is assigned the normal QoS policy profile If needed you can create other QoS policy profiles and apply them to different traffic types so that they have dif...

Page 18: ...ow the threshold This system prevents the overwhelming broadcast traffic that can result from network equipment which is faulty or configured incorrectly VLANs A Virtual LAN VLAN is a flexible group of devices that can be located anywhere in a network but which communicate as if they are on the same physical segment With VLANs you can segment your network without being restricted by physical conne...

Page 19: ...OM that accompanies your Switch Port Features The default state for all the features detailed below provides the best configuration for most users In normal operation you do not need to alter the Switch from its default state However under certain conditions you may wish to alter the default state of these ports for example if you want to force a port to operate at 10 Mbps Duplex Full duplex allow...

Page 20: ...Mbps and flow control When auto negotiation is enabled default a port advertises its maximum capabilities these capabilities are by default the parameters that provide the highest performance supported by the port You can modify the capabilities that a port advertises on a per port basis dependent on the type of port You can disable auto negotiation on all fixed ports on the Switch or on a per por...

Page 21: ... unacceptably high error rate or a poor quality cable If both ends of the link support 100 1000 Mbps auto negotiation then auto sensing tunes the link to 100 Mbps to provide an error free 100 Mbps connection to the network An SNMP Trap is sent every time a port is down rated to a lower speed Conditions that affect smart auto sensing Smart auto sensing will not operate on links that do not support ...

Page 22: ...n aggregated link How 802 3ad Link Aggregation Operates Your Switch supports IEEE 802 3ad standard aggregated links which uses the Link Aggregation Control Protocol LACP LACP provides automatic point to point redundancy between two devices switch to switch or switch to server that have full duplex connections operating at the same speed By default LACP is disabled on the 10 100 1000BASE T and GBIC...

Page 23: ...of 802 3ad can be configured and managed via network management Implementing 802 3ad Aggregated Links LACP can be enabled or disabled on a per port basis You can implement 802 3ad aggregated links in three ways Manual Aggregations You can manually add and remove ports to and from an aggregated link via Web or CLI commands However if a port has LACP enabled if a more appropriate or correct automati...

Page 24: ...e partner device and if no matching pre configured aggregated links exist LACP will automatically assign a free un configured aggregated link to form an aggregated link with the partner device The aggregated link will inherit its configuration from the first port originally detected against the partner device If you have an existing single port connection between two devices this automatic behavio...

Page 25: ...emaining devices will each only have one link made active that is passing data All other links will be made inactive to prevent loops occurring LACP detects if one of the existing four aggregated links is removed and will then automatically assign one of the remaining devices to the aggregated link that has become free When multiple links of different speed connect two devices only the highest spe...

Page 26: ...following To be an active participant in an aggregated link the member link ports must operate in full duplex mode If a member link port does not operate in full duplex mode it can still be a member of an aggregated link but it will never be activated If ports of a different speed are aggregated together the higher speed links carry the traffic The lower speed links only carry the traffic if the h...

Page 27: ...k If you do not remove the connection and only disable one end of the member link port traffic is still forwarded to that port by the aggregated link port at the other end This means that a significant amount of traffic may be lost Before removing all member links from an aggregated link you must disable all the aggregated link member ports or disconnect all the links except one if you do not a lo...

Page 28: ...c to the remaining ports Aggregated links therefore provide built in resilience for your network Aggregated Link Example The example shown in Figure 5 illustrates an 4 Gbps aggregated link between two Switch units Figure 5 A 4 Gbps aggregated link between two Switch units To set up this configuration 1 Add the 1000BASE T ports on the upper unit to the aggregated link 2 Add the 1000BASE T ports on ...

Page 29: ... upper Switch to the 1000BASE T port marked Down on the lower Switch 7 Connect the GBIC port marked 27 on the upper Switch to the GBIC port marked 27 on the lower Switch 8 Connect the GBIC port marked 28 on the upper Switch to the GBIC port marked 28 on the lower Switch ...

Page 30: ...32 CHAPTER 2 OPTIMIZING BANDWIDTH ...

Page 31: ...t A multicast is a packet that is intended for one to many and many to many communication Users explicitly request to participate in the communication by joining an endstation to a specific multicast group If the network is set up correctly a multicast can only be sent to an endstation or a subset of endstations in a LAN or VLAN that belong to the relevant multicast group Multicast group members c...

Page 32: ...ice QoS There are situations where a multicast approach is more logical and efficient than a unicast approach Application examples include distance learning transmitting stock quotes to brokers and collaborative computing A typical use of multicasts is in video conferencing where high volumes of traffic need to be sent to several endstations simultaneously but where broadcasting that traffic to al...

Page 33: ...at wish to join a multicast group and then sets its filters accordingly Query Mode Query mode allows the Switch to function as the Querier if it has the lowest IP address in the subnetwork to which it belongs IGMP querying is disabled by default on the Switch 4200 Series This helps prevent interoperability issues with core products that may not follow the lowest IP address election method You can ...

Page 34: ...he LAN or VLAN However as the Switch only has an IP address on its default VLAN the Switch will only ever query on the default VLAN VLAN1 Therefore if there are no other queriers on other VLANs the IP multicast traffic will not be forwarded on them 2 When an IP endstation receives a query packet it sends a report packet back that identifies the multicast group that the endstation would like to joi...

Page 35: ... If IGMP multicast learning is not enabled then IP multicast traffic is always forwarded that is it floods the network For information about configuring IGMP functionality on an endstation refer to the user documentation supplied with your endstation or the endstation s Network Interface Card NIC ...

Page 36: ...38 CHAPTER 3 USING MULTICAST FILTERING ...

Page 37: ... please refer to the Management Interface Reference Guide supplied in HTML format on the CD ROM that accompanies your Switch Spanning Tree Protocol STP The Spanning Tree Protocol STP makes your network more resilient to link failure and also provides a protection from loops one of the major causes of broadcast storms STP is enabled by default on your Switch To be fully effective STP must be enable...

Page 38: ... allows a port that is connected to an endstation to begin forwarding traffic after only four seconds During these four seconds RSTP or STP will detect any misconfiguration that may cause a temporary loop and react accordingly If you have Fast Start disabled on a port the Switch will wait for 30 seconds before RSTP or STP lets the port forward traffic Easy deployment throughout a legacy network th...

Page 39: ... others using two paths Without STP enabled this configuration creates loops that cause the network to overload Figure 7 A network configuration that creates loops Figure 8 shows the result of enabling STP on the bridges in the configuration STP detects the duplicate paths and prevents or blocks one of them from forwarding traffic so this configuration will work satisfactorily STP has determined t...

Page 40: ...e B STP determines which is the most efficient path between each bridged segment and a specifically assigned reference point on the network Once the most efficient path has been determined all other paths are blocked Therefore in Figure 7 Figure 8 and Figure 9 STP initially determined that the path through Bridge C was the most efficient and so blocked the path through Bridge B After the failure o...

Page 41: ...h link usually determined by the bandwidth of the link the higher the cost the less efficient the link Table 3 shows the default port costs for a Switch Table 3 Default port costs STP Calculation The first stage in the STP process is the calculation stage During this stage each bridge on the network transmits BPDUs that allow the system to work out Port Speed Link Type Path Cost 802 1D 1998 Path C...

Page 42: ...er all the bridges on the network have agreed on the identity of the Root Bridge and have established the other relevant parameters each bridge is configured to forward traffic only between its Root Port and the Designated Bridge Ports for the respective network segments All other ports are blocked which means that they are prevented from receiving or forwarding traffic STP Reconfiguration Once th...

Page 43: ...out having to wait to ensure all other bridges in the network have had time to react to the change So the main benefit of RSTP is that the configuration decision is made locally rather than network wide which is why RSTP can carry out automatic configuration and restore a link faster than STP STP Example Figure 10 shows a LAN that has STP enabled The LAN has three segments and each segment is conn...

Page 44: ...costs 300 Y to B 200 B to A 100 Port 2 on Bridge C is therefore selected as the Designated Bridge Port for LAN Segment 3 STP Configurations Figure 11 shows three possible STP configurations using SuperStack 3 Switch units Configuration 1 Redundancy for Backbone Link In this configuration the Switches both have STP enabled and are connected by two links STP discovers a duplicate path and blocks one...

Page 45: ...How STP Works 47 Figure 11 STP configurations ...

Page 46: ...ng the 802 1Q tagged link between Switch B and Switch C By default this link has a path cost of 100 and is automatically blocked because the other Switch to Switch connections have a path cost of 36 18 18 This means that both VLANs are now subdivided VLAN 1 on Switch units A and B cannot communicate with VLAN 1 on Switch C and VLAN 2 on Switch units A and C cannot communicate with VLAN 2 on Switch...

Page 47: ...1 of the Getting Started Guide that accompanies your Switch For detailed descriptions of the web interface operations and the command line interface CLI commands that you require to manage the Switch please refer to the Management Interface Reference Guide supplied in HTML format on the CD ROM that accompanies your Switch How Switch Database Entries Get Added Entries are added to the Switch Databa...

Page 48: ...hat when an endstation is removed from the network its entry is also removed from the database Learned entries are removed from the Switch Database if the Switch is reset or powered down Non aging learned If the aging time is set to 0 seconds all learned entries in the Switch Database become non aging learned entries This means that they are not aged out but they are still removed from the databas...

Page 49: ...raffic queues per port giving it a basic capability to prioritize traffic For more granular prioritization and an enhanced Quality of Service support the SuperStack 3 Switch 4400 is available What is Traffic Prioritization Traffic prioritization allows high priority data such as time sensitive and system critical data to be transferred smoothly and with minimal delay over a network Traffic priorit...

Page 50: ...oys two methods of classifying traffic for prioritization Traffic classification is the means of identifying which application generated the traffic so that a service level can be applied to it The two supported methods for classifying traffic are 802 1D classification is done at layer 2 of the OSI model DiffServ code point classification is done at layer 3 of the OSI model 802 1D traffic classifi...

Page 51: ...l of the packet is not altered by the Switch 4200 Series DiffServ traffic classification DiffServ is an alternative method of classifying traffic so that different levels of service can be applied to it on a network DiffServ is a layer 3 function and the service to be applied is contained within the DSCP field which is in the IP header of a packet 802 1p Service levels Classification 802 1D Low Pr...

Page 52: ...is Received packets in the Switch 4200 Series are checked for DSCP classification and IEEE 802 1D priority The Switch 4200 Series does not set or modify priority levels within the packet The transmitting endstation sets the priority of each packet When the packet is received the Switch places the packet into the appropriate queue depending on its priority level for onward transmission across the n...

Page 53: ...tes No other attributes are supported Traffic queues are preset on a per unit basis on the Switch 4200 Series Configuring traffic prioritization for QoS on a 4200 Series Switch QoS can be configured on your Switch using the 3Com Network Supervisor or via the Command Line Interface CLI The 3Com Network Supervisor application supplied on the CD ROM accompanying your Switch is the main tool for confi...

Page 54: ...service levels will be set somewhere else in the network and not in the Switch 4200 Series Note also that 802 1D service levels are fixed and cannot be altered 3 Create Profiles The next step is to create a profile which associates classifiers with service levels 4 Apply Qos profile After a QoS profile has been created it can be assigned to the Port s When the profile is assigned to the port s the...

Page 55: ...itch allows you to improve your network efficiency and reduce the load on your network This section explains more about RMON It covers the following topics What is RMON Benefits of RMON RMON and the Switch Hardware Status Monitoring What is RMON RMON is a system defined by the IETF Internet Engineering Task Force that allows you to monitor the traffic of LANs or VLANs RMON is an integrated part of...

Page 56: ...aps required by SNMP link up link down warm start cold start and authentication failure RMON adds two more rising threshold and falling threshold Effective use of the Events group saves you time rather than having to watch real time graphs for important occurrences you can depend on the Event group for notification Through the SNMP traps events can trigger other actions therefore providing a way t...

Page 57: ...4 When using the RMON features of the Switch note the following After the default sessions are created they have no special status You can delete or change them as required The greater the number of RMON sessions the greater the burden on the management resources of the Switch If you have many RMON sessions the forwarding performance of the Switch is not affected but you may experience slow respon...

Page 58: ... Event Action No action Notify only Send Trap Notify and filter port Send Trap Block broadcast and multicast traffic on the port Recovers with the unfilter port event Notify and disable port Send Trap Turn port off Notify and enable port Send Trap Turn port on Disable port Turn port off Enable port Turn port on Notify and unfilter port Send Trap Stop blocking broadcast and multicast traffic on the...

Page 59: ...receive notification via email SMS Short Message Service or pager of the event that has occurred This feature uses an SMTP Simple Mail Transfer Protocol email client to send the notification email The Short Message Service SMS and pager messages are constrained on message size so they are sent to a different email address which creates the message to be displayed and then forwards it on to the SMS...

Page 60: ...e Status Monitoring Your Switch has a fan monitoring system that will generate fan failure warning messages Fan failure could potentially reduce the lifetime of the Switch The monitoring system polls the fan status at periodic intervals while the unit is powered up Should a failure occur a warning notification will be generated in one of the following ways Via the CLI menu An indication of a gener...

Page 61: ...bridge Administer bridge wide parameters gettingStarted Basic device configuration logout Logout of the Command Line Interface physicalInterface Administer physical interfaces protocol Administer protocols security Administer security system Administer sytem level functions trafficManagement Administer traffic management Type For help 1 Select menu option system summary Select menu option system S...

Page 62: ...mmary web page RMON Trap See Events on page 58 for details of this feature of your Switch RMON Event Notification Event Notification for fan failure can be configured by the User refer to Email Notification of Events on page page 61 for details of this feature of your Switch ...

Page 63: ...e supplied in HTML format on the CD ROM that accompanies your Switch What are VLANs A VLAN is a flexible group of devices that can be located anywhere in a network but which communicate as if they are on the same physical segment With VLANs you can segment your network without being restricted by physical connections a limitation of traditional network design As an example with VLANs you can segme...

Page 64: ...and changes If users move to a different subnetwork the addresses of each endstation must be updated manually With a VLAN setup if an endstation in VLAN Marketing for example is moved to a port in another part of the network and retains its original subnet membership you only need to specify that the new port is in VLAN Marketing You do not need to carry out any re cabling VLANs provide extra secu...

Page 65: ...does not perform any VLAN filtering As a result a tagged packet will be forwarded if the address has been previously learned by the Switch However if the address is unknown the packet will only be flooded to ports within the VLAN s on which the receive port is a member The IEEE 802 1Q standard allows each port on your Switch to be placed in Any one VLAN defined on the Switch Several VLANs at the s...

Page 66: ...ing New VLANs If you want to move a port from the Default VLAN to another VLAN you must first define information about the new VLAN on your Switch VLANs Tagged and Untagged Membership Your Switch supports 802 1Q VLAN tagging a system that allows traffic for multiple VLANs to be carried on a single physical backbone link When setting up VLANs you need to understand when to use untagged and tagged m...

Page 67: ...n a Single VLAN Once the information for a new VLAN has been defined you can place a port in that VLAN Creating an IEEE 802 1Q Tagged Link This method of tagging is defined in the IEEE 802 1Q standard and allows a link to carry traffic for any of the VLANs defined on your Switch 802 1Q tagging can only be used if the devices at both ends of a link support IEEE 802 1Q To create an 802 1Q tagged lin...

Page 68: ...handled by the single Switch and therefore untagged connections can be used The example shown in Figure 20 illustrates a single Switch connected to endstations and servers using untagged connections Ports 1 2 and 3 of the Switch belong to VLAN 1 ports 10 11 and 12 belong to VLAN 2 VLANs 1 and 2 are completely separate and cannot communicate with each other This provides additional security for you...

Page 69: ...mple shown in Figure 21 illustrates two Switch units Each switch has endstations and a server in VLAN 1 and VLAN 2 All endstations in VLAN 1 need to be able to connect to the server in VLAN1 which is attached to Switch 1 and all endstations in VLAN 2 need to connect to the server in VLAN2 which is attached to Switch 2 Figure 21 VLAN configuration example 802 1Q tagged connections To set up the con...

Page 70: ... Place the endstation ports in the appropriate VLANs as untagged members 6 Add port 11 on Switch 2 to the VLANs Add port 11 on Switch 2 as a tagged member of both VLANs 1 and 2 so that all VLAN traffic is passed over the link to Switch 1 7 Check the VLAN membership for both switches The relevant ports should be listed in the VLAN members summary 8 Connect the switches Connect port 12 on Switch 1 t...

Page 71: ... For detailed information on setting up your Switch for management see the Getting Started Guide that accompanies your Switch For detailed descriptions of the web interface operations and the command line interface CLI commands that you require to manage the Switch please refer to the Management Interface Reference Guide supplied in HTML format on the CD ROM that accompanies your Switch For backgr...

Page 72: ...l BOOTP For ease of use you do not have to choose between these three automatic configuration methods The Switch tries each method in a specified order as described in Automatic Process on page 75 Manual IP Configuration you can manually input the IP information IP address subnet mask and default gateway If you select an option for no IP configuration the Switch will not be accessible from a remot...

Page 73: ...ocol ARP to check to make sure this address is not already in use on the network If not it will allocate this default address to the Switch If this IP address is already in use Auto IP will check once every second for three seconds for an IP address on the 169 254 x y subnet where x 1 254 and y 0 255 Auto IP only uses addresses in the range 169 254 1 0 through to 169 254 254 255 as valid addresses...

Page 74: ...ystems Microsoft Windows 2000 Server Microsoft Windows NT4 Server Sun Solaris v2 5 1 If you want DHCP or BOOTP to be the method for automatic configuration make sure that your DHCP or BOOTP servers are operating normally before you power on your Switch Event Log Entries and Traps An event log will be generated and an SNMP trap will be sent if any of the following changes occur in the IP configurat...

Page 75: ...II APPENDICES AND INDEX Appendix A Configuration Rules Appendix B Network Configuration Examples Appendix C IP Addressing Glossary Index ...

Page 76: ...78 ...

Page 77: ...04 ft Category 5 cabling with connections up to 100 m 328 ft The different types of Gigabit Ethernet media and their specifications are detailed in Table 7 Table 7 Gigabit Ethernet cabling Gigabit Ethernet Transceivers Fiber Type Modal Bandwidth MHz km Lengths Supported Specified by IEEE meters 1000BASE LX 1000BASE SX 1000BASE T MM Multimode 62 5 µm MM 50 µm MM 50 µm MM 10 µm SM 62 5 µm MM 62 5 µm...

Page 78: ...w they allow for large scale Fast Ethernet networks Figure 22 Fast Ethernet configuration rules The key topology rules are Maximum UTP cable length is 100 m 328 ft over Category 5 cable A 412 m 1352 ft fiber link is allowed for connecting switch to switch or endstation to switch using half duplex 100BASE FX A total network span of 325 m 1066 ft is allowed in single repeater topologies one hub stac...

Page 79: ...rovides full duplex support for all its ports including Expansion Module ports Full duplex allows packets to be transmitted and received simultaneously and in effect doubles the potential throughput of a link With full duplex the Ethernet topology rules are the same but the Fast Ethernet rules are Maximum UTP cable length is 100 m 328 ft over Category 5 cable A 2 km 6562 ft fiber link is allowed f...

Page 80: ...82 APPENDIX A CONFIGURATION RULES ...

Page 81: ...r contains the following sections Simple Network Configuration Examples Segmentation Switch Example Desktop Switch Example Advanced Network Configuration Examples Improving the Resilience of Your Network Enhancing the Performance of Your Network ...

Page 82: ...Mbps and 100 Mbps connections There is a 10 100 shared segment on each floor and these segments are connected to the Switch which is positioned in the basement Figure 23 Using the Switch 4200 Series to segment your network Switch 4200 series stack Dual Speed Hub 500 Dual Speed Hub 500 Endstations on shared 10 Mbps and 100 Mbps connections Endstations on shared 10 Mbps and 100 Mbps connections Ends...

Page 83: ...nections to the desktop The Switch 4200 Series stack has a 1000BASE T Module fitted that allows it to provide a Gigabit Ethernet link to a Switch 4900 in the basement Figure 24 Using the Switch 4200 Series in a desktop environment Switch 4200 Series stack Switch 4900 Endstations on 10 Mbps 100 Mbps connections Local server on a switched 1000 Mbps connection Servers on a 1000 Mbps connection 1000 M...

Page 84: ... this increases the bandwidth available for the backbone connection and also provides extra resilience Figure 25 Network set up to provide resilience Endstations on 10 100 Mbps connections 1000 Mbps 100 Mbps Servers on 1000 Mbps connections with resilient links set up 1000 Mbps with aggregated links set up Server on 1000 Mbps connection with resilient links set up Server on 1000 Mbps connection wi...

Page 85: ...n A Gigabit Ethernet backbone is set up between the Switch 4900 and each Switch in the workgroups to increase the bandwidth and therefore the overall network performance Figure 26 Network set up to enhance performance Endstations on 10 100 Mbps connections Endstations on 10 100 Mbps connections Stack of four Switch 4200 Series units 1000 Mbps 100 Mbps Switch 4900 Switch 4200 Series unit Servers on...

Page 86: ...88 APPENDIX B NETWORK CONFIGURATION EXAMPLES ...

Page 87: ...dress is Advanced Overview Gives a more in depth explanation of IP addresses and the way they are structured Simple Overview To operate correctly each device on your network must have a unique IP address IP addresses have the format n n n n where n is a decimal number between 0 and 255 An example IP address is 192 168 100 8 The IP address can be split into two parts The first part called the netwo...

Page 88: ... Registration Services is the organization responsible for supplying registered IP addresses The following contact information is correct at time of publication World Wide Web site http www internic net Advanced Overview IP addresses are 32 bit addresses that consist of a network part the address of the network where the host is located and a host part the address of the host on that network Figur...

Page 89: ...classes of IP addresses are as follows Class A address Uses 8 bits for the network part and 24 bits for the host part Although only a few Class A networks can be created each can contain a very large number of hosts Class B address Uses 16 bits for the network part and 16 bits for the host part Class C address Uses 24 bits for the network part and 8 bits for the host part Each Class C network can ...

Page 90: ...s a subnetwork part a subnet mask identifies the bits that constitute the subnetwork address and the bits that constitute the host address A subnet mask is a 32 bit number in the IP address format The 1 bits in the subnet mask indicate the network and subnetwork part of the address The 0 bits in the subnet mask indicate the host part of the IP address as shown in Figure 29 Figure 29 Subnet Masking...

Page 91: ...0 The number that includes both the Class B natural network mask 255 255 and the subnet mask 255 240 is sometimes called the extended network prefix Continuing with the previous example the subnetwork part of the mask uses 12 bits and the host part uses the remaining 4 bits Because the octets are actually binary numbers the number of subnetworks that are possible with this mask is 4 096 212 and th...

Page 92: ...gments When it receives the IP packets the gateway determines the next network hop on the path to the remote destination and sends the packets to that hop This could either be the remote destination or another gateway closer towards the destination This hop by hop process continues until the IP packets reach the remote destination If manually configuring IP information for the Switch enter the IP ...

Page 93: ...aging The automatic removal of dynamic entries from the Switch Database which have timed out and are no longer valid Aggregated Links Aggregated links allow a user to increase the bandwidth and resilience between switches by using a group of ports to carry traffic between the switches auto negotiation A feature on twisted pair ports that allows them to advertise their capabilities for speed duplex...

Page 94: ...twork bandwidth and can cause a network to fail Broadcast storms can be due to faulty network devices cache Stores copies of frequently accessed objects locally to users and serves them to users when requested Classifier Classifies the traffic on the network Traffic classifications are determined by protocol application source destination and so on You can create and modify classifications The Swi...

Page 95: ...ps over a variety of cables Ethernet address See MAC address Fast Ethernet An Ethernet system that is designed to operate at 100Mbps forwarding The process of sending a packet toward its destination using a networking device Forwarding Database See Switch Database filtering The process of screening a packet for certain characteristics such as source address destination address or protocol Filterin...

Page 96: ...ounded in 1963 and sets standards for computers and communications IEEE 802 1D A standard that defines the behavior of bridges in an Ethernet network IEEE 802 1p A standard that defines traffic prioritization 802 1p is now incorporated into the relevant sections of the IEEE 802 1D D17 standard IEEE 802 1Q A standard that defines VLAN tagging IEEE 802 3x A standard that defines a system of flow con...

Page 97: ...ernetwork Packet Exchange IPX is a layer 3 and 4 network protocol designed for networks that use Novell Netware IP address Internet Protocol address A unique identifier for a device attached to a network using TCP IP The address is written as four octets separated with periods full stops and is made up of a network section an optional subnet section and a host section Jitter An expression often us...

Page 98: ...the receiver of another device MDI X Medium Dependent Interface Cross over An Ethernet port connection where the internal transmit and receive lines are crossed MIB Management Information Base A collection of information about the management characteristics and parameters of a networking device MIBs are used by the Simple Network Management Protocol SNMP to gather information about the devices on ...

Page 99: ...other fail See also main port and standby port RMON IETF Remote Monitoring MIB A MIB that allows you to remotely monitor LANs by addressing up to nine different groups of information router A router is a device on your network which is used to forward IP packets to a remote destination An alternative name for a router is a gateway RPS Redundant Power System A device that provides a backup source o...

Page 100: ...ort in a resilient link that takes over data transmission if the main port in the link fails STP See Spanning Tree Protocol STP subnet mask A subnet mask is used to divide the device part of the IP address into two further parts The first part identifies the subnet number The second part identifies the device on that subnet switch A device that interconnects several LANs to form a single logical L...

Page 101: ...ified using one or more of types of traffic classifiers A classifier detects the packet attributes and classifies the traffic accordingly traffic prioritization A system which allows data that has been assigned a high priority to be forwarded through a switch without being obstructed by other data unicast A packet sent to a single endstation on a network VLAN Virtual LAN A group of location and to...

Page 102: ...104 GLOSSARY ...

Page 103: ... 59 conventions notice icons About This Guide 10 text About This Guide 10 D default gateway 94 Default VLAN 67 Designated Bridge 44 Designated Bridge Port 44 DHCP 16 74 E event notification 19 61 Events RMON group 58 59 extended network prefix 93 F Fan failure status monitoring 62 Fast Ethernet configuration rules 80 Filter RMON group 58 59 flow control 22 full duplex configuration rules 81 G Giga...

Page 104: ... QoS apply QoS profile 56 configuring traffic on a Switch 4200 55 creating profiles 56 How traffic is processed to provide QoS 55 service levels 56 traffic classification 55 Quality of Service 19 R Rapid Spanning Tree Protocol RSTP 18 40 registered IP address obtaining 90 Remote Monitoring See RMON RMON 19 61 alarm events 60 benefits 58 default alarm settings 60 groups 58 Root Bridge 43 Root Path ...

Page 105: ...nets Switch Database 49 T topology rules for Fast Ethernet 80 topology rules with full duplex 81 traffic classification 802 1D 52 traffic prioritization 51 802 1D 52 V VLANs 65 802 1Q tagging 69 benefits 66 communication between 68 Default 67 defining the information for 68 IEEE 802 1Q 67 placing ports in multiple 69 ...

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