Cisco Systems NME-16ES-1G manual Virtual IP Addresses in Clusters

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Cisco EtherSwitch Service Modules Feature Guide

Information About the Cisco EtherSwitch Service Modules

Virtual IP Addresses in Clusters

You need to assign a unique virtual IP address and group number and name to the cluster standby group. This information must be configured on a specific VLAN or routed port on the active cluster command switch. The active cluster command switch receives traffic destined for the virtual IP address. To manage the cluster, you must access the active cluster command switch through the virtual IP address, not through the command-switch IP address. This is in case the IP address of the active cluster command switch is different from the virtual IP address of the cluster standby group.

If the active cluster command switch fails, the standby cluster command switch assumes ownership of the virtual IP address and becomes the active cluster command switch. The passive switches in the cluster standby group compare their assigned priorities to decide the new standby cluster command switch. The passive standby switch with the highest priority then becomes the standby cluster command switch. When the previously active cluster command switch becomes active again, it resumes its role as the active cluster command switch, and the current active cluster command switch becomes the standby cluster command switch again. For more information about IP address in switch clusters, see the “IP Addresses in Clusters” section on page 30.

Other Considerations for Cluster Standby Groups

Note For additional considerations about cluster standby groups in switch stacks, see the “Switch Clusters and Switch Stacks” section on page 31.

These requirements also apply:

•Standby cluster command switches must be the same type of switches as the cluster command switch. For example, if the cluster command switch is a Cisco EtherSwitch service module, the standby cluster command switches must also be Cisco EtherSwitch service modules or Catalyst 3750 switches. See the switch configuration guide of other cluster-capable switches for their requirements on standby cluster command switches.

If the switch cluster has a Cisco EtherSwitch service module, Catalyst 3750 switch or switch stack, that switch or switch stack must be the cluster command switch.

•Only one cluster standby group can be assigned to a cluster. You can have more than one router-redundancy standby group.

An HSRP group can be both a cluster standby group and a router-redundancy group. However, if a router-redundancy group becomes a cluster standby group, router redundancy becomes disabled on that group. You can reenable it by using Network Assistant or the CLI. For more information about HSRP and router redundancy, see the Catalyst 3750 Switch Software Configuration Guide, Cisco IOS Release 12.2 at http://www.cisco.com/univercd/cc/td/doc/product/lan/cat3750/index.htm.

•All standby-group members must be members of the cluster.

Note There is no limit to the number of switches that you can assign as standby cluster command switches. However, the total number of switches in the cluster—which would include the active cluster command switch, standby-group members, and cluster member switches—cannot be more than 16.

Cisco IOS Release 12.2(25)SEC

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Contents Guide Release ModificationContents Network Modules Hardware Installation Guide Hardware OverviewSoftware Features and Benefits Ease-of-Use and Ease-of-Deployment Features Performance FeaturesManagement Options Manageability Features Availability FeaturesVlan Features Security Features QoS and CoS Features Power-over-Ethernet Features Monitoring FeaturesOverview of Switch Stacks Cisco StackWise ConceptsSwitch Stack Membership Stack Master Election and Re-Election Switch Stack Bridge ID and Router MAC Address Stack Member NumbersStack Member Priority Values Switch Stack Software Compatibility Recommendations Stack Protocol Version CompatibilitySwitch Stack Configuration Files Switch Stack Management Connectivity Clustering Concepts Accessing the CLI of a Specific Stack MemberManagement Connectivity to Specific Stack Members Standby Command Device Characteristics Command Device CharacteristicsCluster Compatibility Automatic Discovery of Candidates and Members Candidate and Member CharacteristicsDiscovery of Candidates and Members Through CDP Hops Vlan Discovery of Candidates and Members Through Different VLANs Switch Discovery of Candidates and Members Through Routed PortsDiscovery of Newly Installed Switches in Clusters New out-of-boxHsrp and Standby Cluster Command Switches Virtual IP Addresses in Clusters Other Considerations for Cluster Standby GroupsAutomatic Recovery of Cluster Configuration IP Addresses in Clusters Hostnames in ClustersPasswords in Clusters Switch Clusters and Switch StacksSwitch Stack Switch Cluster Snmp Community Strings in ClustersSwitch Stack Switch Cluster Availability of Switch-Specific Features in Switch Clusters TACACS+ and Radius in ClustersCisco IOS Release 12.225SEC Using Interface Configuration Mode Command or Action Purpose Boot flash image-nameExample Dir flashEnable Show running configurationConfigure terminal Service-module interface slot/port sessionShow power inline Output of the show service-module status commandShow ip interface brief Control+shift+6Sample Output for the dir flash Command on the Router Sample Output for the boot flash Command on the RouterRouter boot flashc2800-adventerprisek9-mz ExamplesRouter# show running config interface gigabitethernet2/0 Router# configure terminalRouter# service-module gigabitethernet2/0 session Switch dir flashSwitch# show ip interface brief Switch# ctrl+shift+6Switch# show power inline Sample Output for Pressing Ctrl+Shift+6 Followed byFeature Default Setting DhcpSTP Prerequisites Clustering Concepts section on Return Sample Output for Entering an Interface Name Sample Output for Assigning the IP Address and Subnet MaskSample Output for Saving the Configuration to Nvram Command or Action PurposeRouter# service-module gigabitethernet1/0 reset Router# service-module gigabitethernet1/0 shutdownRouter# service-module gigabitethernet1/0 reload Cisco IOS Release 12.225SEC Default Switch Stack Configuration RestrictionsAssigning a Stack Member Number Sample Output for the switch renumber Command Sample Output for the reload slot CommandShow switch Switchconfig# switch 6 renumberSetting the Stack Member Priority Value Sample Output for the show switch CommandVerifying Information About the Switch Stack Sample Output for the switch priority CommandSwitchconfig# switch 2 priority Switch show switchSwitch# show platform stack-manager all Switchconfig# show switch neighbors Show switch stack-portsRcommand Using the CLI to Manage Switch ClustersShow version Sample Output for the rcommand and show version Commands Sample Output for the show cluster members CommandChoose View Refresh Choose Cluster Add to Cluster or Password Cluster memberCreating a Cluster Standby Group Detailed Steps from the CLICluster standby-group HSRP-group-name Routing-redundancyNo switchport Sample Output for the ping tftpserver Command Sample Output for the show flash Command Sample Output for the copy tftp flash CommandSwitch# show flash Switch# copy tftp flashRecovering from a Corrupted Software Image Using Xmodem Service-module interface slot/port password-reset FlashinitService-module interface slot/port Password-resetFlashinit Control+6Sample Output for the copy flash xmodem Command TroubleshootingRouter# copy flash xmodem Sample Output for the copy tftp xmodem Command Router# copy tftp xmodemRouter# service-module gigabitethernet1/0 session Router# service-module gigabitethernet2/0 password-resetRecovering from a Lost or Forgotten Password Optional loadhelper filesystem/file-url Boot -x -v deviceimagename Enable secret passwordRename Copy flashCopy running-configuration startup-configuration ReloadOptional set Service-module password-reset command BootExample Sample Output for the set CommandSet Scenario Action Result Current-stack-member-number Renumber new-stack-member-number Network Configuration Examples Network Demands Suggested Design Methods Cost-Effective Wiring Closet Redundant Gigabit Backbone Cisco SoftPhone Software 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