Configure a backup route

Last published : Sep 22, 2026
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.
Figure 1. Backup Route Setup
Backup Route Setup
Note: If your ISP has provided an IPv6 address, replace the IPv4 service with an IPv6 service in the preceding figure.
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.
Figure 2. Back up Routing in Operation
Back up Routing in Operation
Note: If your ISP has provided an IPv6 address, replace the IPv4 service with an IPv6 service in the preceding figure.
Related information

To set the secondary virtual server as the backup virtual server by using the command line interface

At the command prompt, type:
set lb vserver <name> -backupVserver <string>
Example:

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

To set the secondary virtual server as the backup virtual server by using the configuration utility

  1. Navigate to Traffic Management > Load Balancing > Virtual Servers and select the secondary virtual server for which you want to configure the backup virtual server.
  2. In the Load Balancing Virtual Server dialog box, under Advanced, select Protection.
  3. In the Backup Virtual Server drop-down list, select the secondary backup virtual server, and then click OK.