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spalande's avatar
spalande
Icon for Nacreous rankNacreous
Sep 23, 2013

Need help for iRule

Need help on iRule for mapping private IP hosted on GTM (A record) to public IP (owned by customer DMZ).   eg. 192.168.4.242 is the private IP hosted on GTM, while sending DNS response need to map...
StephanManthey's avatar
StephanManthey
Icon for Nacreous rankNacreous
Sep 25, 2013

Testing for A records in the response is already build in and would be logged: 

when DNS_REQUEST {
        if {[DNS::question type] ne "A"} {
        log local0. "incoming query for [DNS::question name] is of type [DNS::question type]"
    }
}
when DNS_RESPONSE {
    foreach item [DNS::answer] {
        if {[DNS::type $item] eq "A"} {
            log local0. "[DNS::rdata $item]"
            log local0. "[DNS::type $item]"
            if { [class match -value [DNS::rdata $item] equals dg_internal_external] eq "" } {
                log local0. "no match for internal A record [DNS::rdata $item]"
                DNS::rdata $item 10.141.141.10
            } else {
                log local0. "[class match -value [DNS::rdata $item] equals dg_internal_external]"
                DNS::rdata $item [class match -value [DNS::rdata $item] equals dg_internal_external]
            }
        } else {
            log local0. "[DNS::type $item]"
        }
    }
}

The log will show now: 

incoming query for test.lb-net.bit is of type AAAA