Cisco Services Modules

HTTP Redirect for the Content Switching Module Configuration Example

Document ID: 47960

Updated: Aug 04, 2004



This document provides a sample configuration for configuring HTTP redirect on the Content Switching Module (CSM). Redirects can be used to send a client to a remote site when, for example, the main site is down for maintenance or any other reason.



There are no specific requirements for this document.

Components Used

The information in this document is based on these software and hardware versions:

  • CSM version 3.x

  • Native IOS 12.1E

The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, make sure that you understand the potential impact of any command.

Related Products

This configuration can also be used with these hardware and software versions:

  • CatOS 7.x

  • Multilayer Switch Feature Card (MSFC) IOS 12.1E


For more information on document conventions, refer to the Cisco Technical Tips Conventions.


In this section, you are presented with the information to configure the features described in this document. This configuration allows the CSM of site A to redirect the client to site B when the server at site A is down.

Note: To find additional information on the commands used in this document, use the Command Lookup Tool (registered customers only) .

Network Diagram

This document uses this network setup:



This document uses this configuration:

 vlan 499 client
  ip address
 vlan 500 server
  ip address
  route gateway
 probe WEB_PING icmp

!--- This probe is used to track the availability of local servers.

  interval 2 

!--- The ping interval has been reduced to two seconds to quickly detect a server down.

  retries 2 
  failed 10 
 serverfarm WEBFARM

!--- This is the local serverfarm.

  nat server 
  no nat client

!--- You may have many Web servers here; only one is used for this example.

  probe WEB_PING

!--- Specified the probe to be used as WEB_PING to detect when servers 
!--- are going down.

 serverfarm WEB_REDIRECT

!--- This is the redirect configuration.

  nat server 

!--- NATing does not matter here because traffic is redirected.

  no nat client
  redirect-vserver TENSION

!--- Issue the redirect-vserver name
!--- command to enter the relocation mode.
!--- This replaces the configuration of the real servers.

   webhost relocation

!--- In this example, the traffic is redirected to IP address

!--- The IP address is the remote site virtual IP address.

!--- You can also specify a DNS name, such as
!--- The %p at the end tells the CSM to copy the directory path and the file from 
!--- the initial HTTP request of the client.

 vserver WEB
  virtual tcp www
  serverfarm WEBFARM backup WEB_REDIRECT 

!--- The redirect serverfarm is specified as a backup of the local Web farm.
!--- When all servers are down in the local farm, traffic is redirected to the 
!--- remote site.

  persistent rebalance


This section provides information you can use to confirm your configuration is working properly.

  • show mod csm slot probe detail

    show mod csm 4 probe detail 
    probe           type    port  interval retries failed  open   receive
    WEB_PING        icmp     2        2        10             10     
    real            vserver         serverfarm      policy         status
    ------------------------------------------------------------------------------     WEB           WEBFARM    (default)     FAILED
  • show mod csm slot real

    show mod csm 4 real
    real                  server farm      weight  state          conns/hits
    -------------------------------------------------------------------------          WEBFARM          8       FAILED         0   
  • show mod csm slot vserver name name detail

    show mod csm 4 vservers name web
    vserver         type  prot virtual                  vlan state        conns
    WEB             SLB   TCP     ALL  OUTOFSERVICE 0       
    cpu0#show mod csm 4 vservers name web det
    WEB, type = SLB, state = OUTOFSERVICE, v_index = 31
      virtual = bidir, TCP, service = NONE, advertise = FALSE
      idle = 3600, replicate csrp = none, vlan = ALL, pending = 30
      max parse len = 2000, persist rebalance = TRUE
      ssl sticky offset = 0, length = 32
      conns = 0, total conns = 13
      Default policy:
        server farm = WEBFARM, backup = WEB_REDIRECT (no sticky)
        sticky: timer = 0, subnet =, group id = 0
      Policy          Tot matches  Client pkts  Server pkts
      (default)       13           25           17    

You can also verify if the configuration working properly by capturing a sniffer trace and verifying what the CSM returns to an HTTP request to the Web Vserver. It is also possible to determine if this is working by viewing the URL that displays on the browser after the connection has been completed.


There is currently no specific troubleshooting information available for this configuration.

Related Information

Updated: Aug 04, 2004
Document ID: 47960