BROCADE IP PRIMER

Chapter 14: Security, Redundancy and MoreFinally, we have to activate the VRRP VRID. At this point, the interface isanswering for the virtual address, but there's no router backing it up. Let's fixthat.BR-RouterB#conf tBR-RouterB(config)#router vrrpBR-RouterB(config)#int e 1BR-RouterB(config-if-e1000-1)#ip address 10.1.1.12/24BR-RouterB(config-if-e1000-1)#ip vrrp vrid 1BR-RouterB(config-if-e1000-1-vrid-1)#backup priority 100track-priority 19BR-RouterB(config-if-e1000-1-vrid-1)#track-port e 4BR-RouterB(config-if-e1000-1-vrid-1)#ip-address 10.1.1.11BR-RouterB(config-if-e1000-1-vrid-1)#activateNotice that the configuration is very similar to Router A's. The “backup priority”defines this router's priority number (“100”). As 100 is a lower number than255 (Router A's priority), Router B will not answer for the virtual address. IfRouter A fails, Router B will take over. If Router A's e 1 fails, Router B will notget answers to its hello packets, and take over. If Router A's e 4 fails, its prioritywill change to 20, which is lower than 100. This means, again, Router B wouldassume command. If Router A's e 4 link were to be restored, Router A's prioritywould change to 255 again, and, as this is higher than 100, Router A wouldassume command of the virtual address.Notice that Router B is also tracking its own e 4 interface. After all, if that goesdown, Router B is useless. In this example, if Router B's e 4 fails, its priority willbecome 19. If Router A's e 4 fails as well, Router A will still answer for the virtualaddress, because its priority will be 20 (higher than 19). It won't do thehost any good, but I just thought I'd walk you through the process.Now we may assign 10.1.1.11 as Host A's default gateway, and we will be preparednot only if one router fails, but if one Internet link fails as well. Theworkstation will do nothing.312 Brocade IP Primer