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High Availability Commands for CCNP BCMSN

Chapter Description

This chapter provides information on and commands for Hot Standby Routing Protocol, Virtual Router Redundancy Protocol, and Gateway Load Balancing Protocol.

Gateway Load Balancing Protocol

Gateway Load Balancing Protocol (GLBP) protects data traffic from a failed router or circuit, like HSRP and VRRP, while allowing packet load sharing between a group of redundant routers.

Configuring GLBP

Router(config)# interface fastethernet 0/0

Moves to interface config mode

Router(config-if)# ip address 172.16.100.5 255.255.255.0

Assigns IP address and netmask

Router(config-if)# glbp 10 ip 172.16.100.1

Enables GLBP for group 10 on this interface with a virtual address of 172.16.100.1. The range of group numbers is from 0 to 1023.

Router(config-if)# glbp 10 preempt

Configures the router to preempt, or take over, as the active virtual gateway (AVG) for group 10 if this router has a higher priority than the current AVG

Router(config-if)# glbp 10 preempt delay minimum 60

Configures the router to preempt, or take over, as AVG for group 10 if this router has a higher priority than the current active virtual forwarder (AVF) after a delay of 60 seconds

Router(config-if)# glbp 10 forwarder preempt

Configures the router to preempt, or take over, as AVF for group 10 if this router has a higher priority than the current AVF. This command is enabled by default with a delay of 30 seconds.

Router(config-if)# glbp 10 forwarder preempt delay minimum 60

Configures the router to preempt, or take over, as AVF for group 10 if this router has a higher priority than the current AVF after a delay of 60 seconds

Router(config-if)# glbp 10 priority 150

Sets the priority level of the router

Router(config-if)# glbp 10 timers 5 15

Configures the hello timer to be set to 5 seconds and the hold timer to be 15 seconds

Router(config-if)# glbp 10 timers msec 20200 msec 60600

Configures the hello timer to be 20,200 milliseconds and the hold timer to be 60,600 milliseconds.

Router(config-if)# glbp 10 load-balancing host-dependent

Specifies that GLBP will load balance using the host-dependent method

Router(config-if)# glbp 10 load-balancing weighted

Specifies that GLBP will load balance using the weighted method

Router(config-if)# glbp 10 weighting 80

Assigns a maximum weighting value for this interface for load-balancing purposes. The value can be from 1 to 254.

Router(config-if)# glbp 10 load balancing round robin

Specifies that GLBP will load balance using the round-robin method

If no load balancing is used with GLBP, GLBP will operate in an identical manner to HSRP, where the AVG will only respond to ARP requests with its own VF MAC address, and all traffic will be directed to the AVG.

Verifying GLBP

Router# show running-config

Displays contents of dynamic RAM

Router# show glbp

Displays GLBP information

Router# show glbp brief

Displays a brief status of all GLBP groups

Router# show glbp 10

Displays information about GLBP group 10

Router# show glbp fastethernet 0/0

Displays GLBP information on interface fastethernet 0/0

Router# show glbp fastethernet 0/0 10

Displays GLBP group 10 information on interface fastethernet 0/0

Debugging GLBP

Router# debug condition glbp

Displays GLBP condition messages

Router# debug glbp errors

Displays all GLBP error messages

Router# debug glbp events

Displays all GLBP event messages

Router# debug glbp packets

Displays messages about packets sent and received

Router# debug glbp terse

Displays a limited range of debugging messages

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