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eightsixstud_29's avatar
eightsixstud_29
Icon for Nimbostratus rankNimbostratus
Sep 15, 2016

Error using iRule for Conditional DNS Lookups

I am looking to perform some DNS lookups on a domain and based on the results, either provide the client with the external IP if it exists or the internal IP if there isn't an external A record.   ...
application delivery
BIG-IP DNS
iRules
  • Samir_Jha_52506's avatar
    Samir_Jha_52506
    Sep 15, 2016

    HI,

    Can you please try below irule.

       when DNS_REQUEST {
    if { ([IP::addr [IP::client_addr] equals 192.168.1.0/24]) and ([DNS::rrname] contains "test.com") } {
                        set dnsName [RESOLV::lookup @8.8.8.8 -a [DNS::rrname]] 
                        if { ([DNS::rrtype] equal "A") } {
                            DNS::return
                        } 
        }
    }
Samir_Jha_52506's avatar
Samir_Jha_52506
Icon for Noctilucent rankNoctilucent
Sep 15, 2016

HI,

Can you please try below irule.

   when DNS_REQUEST {
    if { ([IP::addr [IP::client_addr] equals 192.168.1.0/24]) and ([DNS::rrname] contains "test.com") } {
                        set dnsName [RESOLV::lookup @8.8.8.8 -a [DNS::rrname]] 
                        if { ([DNS::rrtype] equal "A") } {
                            DNS::return
                        } 
        }
    }
  • eightsixstud_29's avatar
    eightsixstud_29
    Icon for Nimbostratus rankNimbostratus
    Sep 19, 2016

    We tried using the modified version, but are receiving the same error. Also, we have made the below changes, with no luck. Any ideas? 

    01070151:3: Rule [/Common/Test] error: /Common/Test:2: error: [undefined procedure: DNS::rrname][DNS::rrname]
/Common/Test:4: error: [undefined procedure: DNS::rrtype][DNS::rrtype]

when DNS_REQUEST {
if { ([IP::addr [IP::client_addr] equals 192.168.1.0/24]) and ([DNS::rrname] equals "test.com") } {
                    [RESOLV::lookup @8.8.8.8 -a [DNS::rrname]] 
                    if { ([DNS::rrtype] equals "A") } {
                        DNS::return
                    } 
    }
}