URL Header changes to Node name.

Could you check if the redirect HTTP is coming from your webserver or from your LTM configuration ? I think it's from your WebServer, and your BIG-IP is just forwarding it to your client.

I asked the systems teams. they say they are not doing any redirects. This is really a straight forward Round Robin config. Doesnt call for any redirects. There are lots of profiles, Oneconnect, http Compression, Http Acceleration. Could one of those be the issue?

The issue is not due to your profiles I think.

Just to be sure it's not coming from your webserver, could you apply this iRule to your Virtual Server :

when HTTP_RESPONSE {  
    if { [HTTP::is_redirect] } {
            HTTP::header remove Location  
            HTTP::header insert Location "http://your_Original_DNS_name"    
    }
}

If there's any redirect coming from your webserver it'll be removed and replaced by your Original_DNS_name.

This irule could work but there are three different names mapped to the VIP, depending if you are connecting Internal, Externail or from India. So if you can make the irule preserve URL into the header would work. Since I would be able to hard code the DNS name into the irule.

Here is the iRule giving you the ability to replace informations coming from your webservers with the original fqdn requested.

when HTTP_REQUEST {
    set Origin "[HTTP::host][HTTP::uri]"
}

when HTTP_RESPONSE {
    if { [HTTP::is_redirect] } {
        HTTP::header remove Location
        HTTP::header insert Location "http://$Origin"
    }
}