iRule to change host headers.

Hi Steve,

If the response content from the external site contained absolute references to the external domain, then you would want to rewrite these to the internal domain before sending the response back to the client. To do this, you can use the STREAM:: commands. Looking at the external host you had listed, I didn't see any embedded references (href's, img src, etc) to the external site, so I think this is unnecessary in your situation. You could double check this though.

You can combine the two rules you have listed above into a single rule. Also, you can do a case insensitive comparison for the host using string compare. Lastly, you can redirect / to /aon.asp. Here is an untested example:

  
 when RULE_INIT { 
  
     Set the hostname that the client makes request to (do not include protocol)  
    set ::external_hostname "www.mycompany.co.uk"  
  
     Set the hostname that the BIG-IP will rewrite requests to  
    set ::internal_hostname "www.provider.com"  
  
     Redirect / requests to this URI  
    set ::root_redirect_uri "/aon.asp" 
  
     Log debug messages to /var/log/ltm? 1=yes, 0=no.  
    set ::proxy_site_debug 1  
 }  
 when HTTP_REQUEST { 
  
    if {$::proxy_site_debug}{log local0. "Received request from [IP::client_addr] -> [HTTP::host][HTTP::uri]"}  
  
     Check if request is to root document  
    if {[HTTP::path] eq "/"}{ 
  
       if {$::proxy_site_debug}{log local0. \  
          "Redirecting [IP::client_addr] from / -> https://$::external_hostname$::root_redirect_uri"}  
  
        Redirect to internal hostname and root object  
       HTTP::redirect "https://$::external_hostname$::root_redirect_uri"  
  
    } else {  
  
       if {$::proxy_site_debug}{log local0. "Rewriting [IP::client_addr]'s Host header to $::internal_hostname"}  
  
        We're not redirecting so rewrite the Host header   
       HTTP::header replace "Host" $::internal_hostname  
    }  
 }  
 when HTTP_RESPONSE {  
  
     Check if the status indicates a redirect  
    if {[HTTP::is_redirect]} {  
  
       if {$::proxy_site_debug}{log local0. "Rewriting [IP::client_addr]'s redirect to \  
 [string map -nocase $::internal_hostname $::external_hostname [HTTP::header Location]]"}  
  
        Rewrite the Location header replacing the internal hostname with the external hostname  
       HTTP::header replace Location [string map -nocase $::internal_hostname $::external_hostname [HTTP::header Location]]  
    }  
 }  
 

Aaron