Forum Discussion

Danny_Arroyo's avatar
Danny_Arroyo
Icon for Cirrus rankCirrus
Sep 03, 2013

How do I change an incoming uri to a different string before the VIP sends it to the Pool?

I expect the users to enter the following uri: http://server.domain.com/webapplication?frc=AO   I want the irule to convert the uri to the following: http://server.domain.com/flexiblewebapplicatio...
application delivery
devops
iRules
Kevin_Stewart's avatar
Kevin_Stewart
Icon for Employee rankEmployee
Sep 06, 2013

A few things:

 

  1. HTTP::uri changes the request URI value as it passes through the proxy. There's no client side interaction so the browser doesn't see this.

     

  2. Changing the URI does not actually change the value in the HTTP::uri buffer, so (and this actually depends on BIG-IP version) you won't see the modified URI in HTTP::uri. In other words what you're seeing is to be expected.

     

  3. Since the traffic isn't encrypted it doesn't matter where you run the tcpdump. I typically run it from the BIG-IP though because I know the traffic is at least coming from there. So from the BIG-IP management shell (console or SSH), run the following:

     

    tcpdump -lnni [internal VLAN name] -Xs0 host [redhat server IP]

     

If you're getting any traffic at all between the BIG-IP and server, you'll also see what the HTTP looks like - including the URI value.