Product Documentation

Generic Routing FAQs

Mar 20, 2012

Users typically have the following questions about how to troubleshoot generic routing issues:

  • How do I save the config files?

    The write command from VTYSH saves only ZebOS.conf. Run the save ns config command from NetScaler CLI to save both ns.conf and ZebOS.conf files.
  • If I have configured both a static default route and a dynamically learned default route, which is the preferred default route?

    The dynamically learned route is the preferred default route. This behavior is unique to default routes. However, in case of the Network Services Module (NSM), unless the administrative distances are modified, a statically configured route in the RIB is preferred over a dynamic route. The route that is downloaded to the NSM FIB is the static route.

  • How do I block the advertisement of default routes?

    After release 7.0, the default route is not injected into ZebOS.

    However, if you are working with 7.0 or an earlier release, you must apply a suitable route map with the

    However, if you are working with 7.0 or an earlier release, you must apply a suitable route map with the redistribute kernel command for each protocol to block default route advertisement. For example:

    ns(config)#access-list 1 deny 
    ns(config)#access-list 2 permit any 
    ns(config)#route-map redist-kernel permit 5 
    ns(config-route-map)#match ip address 1 
    ns(config)#route-map redist-kernel permit 10 
    ns(config-route-map)#match ip address 2 
    ns(config)#router ospf 1 
    ns(config-router)#redistribute kernel route-map redist-kernel 
    ns#show route-map 
    route-map redist-kernel, permit, sequence 5 
      Match clauses: 
        ip address 1 
      Set clauses: 
    route-map redist-kernel, permit, sequence 10 
      Match clauses: 
        ip address 2 
      Set clauses: 
    ns#show access-list 
    Standard IP access list 1 
    Standard IP access list 2 
        permit any 
  • How do I view the debug output of networking daemons?

    You can write debugging output from networking daemons to a file by entering the following log file command from the global configuration view in VTYSH:
    ns(config)#log file /var/ZebOS.log 
    With release 8.1, you can direct debug output to the console by entering the terminal monitor command from VTYSH user view:
    ns#terminal monitor 
  • How do I collect cores of running daemons?

    You can use the gcore utility to collect cores of running daemons for processing by gdb. This might be helpful in debugging misbehaving daemons without bringing the whole routing operation to a standstill.

    gcore [-s] [-c core] [executable] pid 
    The -s option temporarily stops the daemon while gathering the core image. This is a recommended option, because it guarantees that the resulting image shows the core in a consistent state.
    root@ns#gcore -s -c nsm.core /netscaler/nsm 342 
  • How do I run a batch of ZebOS commands?

    You can run a batch of ZebOS commands from a file by entering the VTYSH -f <file-name> command. This does not replace the running configuration, but appends to it. However, by including commands to delete the existing configuration in the batch file and then add those for the new, desired configuration, you can use this mechanism to replace a specific configuration:

    router bgp 234 
    route-map bgp-out2 permit 10 
     set metric 9900 
     set community 8602:300