To prevent disruption in services when the primary route is down, you can configure a backup route. Once the backup route is configured, the NetScaler appliance automatically uses it when the primary route fails. First create a primary virtual server as described in "Configuring an LLB Virtual Server and Binding a Service." To configure a backup route, create a secondary virtual server similar to a primary virtual server and then designate this virtual server as a backup virtual server (route).
In the following diagram, Router-vip is the primary virtual server, and Backup_Router-vip is the secondary virtual server designated as the backup virtual server.
By default, all traffic is sent through the primary route. However, when the primary route fails, all traffic is diverted to the backup route as shown in the following diagram.
At the command prompt, type:
set lb vserver Router-vip -backupVServer Backup_Router-vip > show lb vserver Router-vip Router-vip (0.0.0.0:0) - ANY Type: ADDRESS State: UP Last state change was at Fri Sep 3 04:46:48 2010 Time since last state change: 0 days, 03:09:45.600 Effective State: UP Client Idle Timeout: 120 sec Down state flush: ENABLED Disable Primary Vserver On Down : DISABLED No. of Bound Services : 1 (Total) 1 (Active) Configured Method: ROUNDROBIN Mode: IP Persistence: DESTIP Persistence Mask: 255.255.255.255 Persistence v6MaskLength: 128 Persistence Timeout: 2 min Backup: Router2-vip Connection Failover: DISABLED Done