Forum Discussion

Altostratus

Mar 26, 2015

GTM iRule to forward dns request to a pool of DNS servers

Hi, On the GTM, is it possible to use an iRule to disable wideIP and forward a dns request to a pool of DNS servers instead? I have a situation where LTM pool members attempt to resolve eac...

KingMeow_3883

Altostratus

Mar 30, 2015

Hi Stephan,

I just tried your suggestion and it seems to do exactly what I wanted. I also added the extra condition that the DNS question must match a certain string.

Thanks a lot for your help 🙂

This is the current iRule I've tested successfully (thanks to Stephan Manthey) for anyone looking at this in future:

when DNS_REQUEST {
if {[IP::addr [IP::client_addr] equals 10.10.10.10/32]} {
    log local0. "dns query from local network: <[IP::client_addr]>"
    set dnsq [DNS::question name]
    log local0. "DNS Question: [DNS::question name]"
    switch -glob $dnsq {
        "blah???blah???.a.b.c.com" {
            log local0. "question matches disabling criteria"
            DNS::disable gtm
        }
    }
}

Regards,

-KingMeow