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mfkk531_168091's avatar
mfkk531_168091
Icon for Nimbostratus rankNimbostratus
Apr 13, 2016

Have to do reverse dns lookup on client IP, and insert the name into http header, and send to server. Help!

I'm currently doing XFF in http profile   I have a requirement to do reverse dns lookup on client IP, and insert the resolved name into http header, which the backend server can pick up.   Th...
application delivery
iRules
LTM
  • ekaleido_26616's avatar
    ekaleido_26616
    Apr 13, 2016

    Maybe this?

     

    when CLIENT_ACCEPTED {

     

    set reverseDns [RESOLV::lookup @8.8.8.8 -ptr [IP::clientaddr]]

     

    }

     

    when HTTP_REQUEST {

     

    HTTP::header insert YOUR_HEADER_NAME $reverseDns

     

    }

     

ekaleido_26616's avatar
ekaleido_26616
Icon for Cirrocumulus rankCirrocumulus

Maybe this?

 

when CLIENT_ACCEPTED {

 

set reverseDns [RESOLV::lookup @8.8.8.8 -ptr [IP::clientaddr]]

 

}

 

when HTTP_REQUEST {

 

HTTP::header insert YOUR_HEADER_NAME $reverseDns

 

}

 

ekaleido_26616's avatar
ekaleido_26616
Icon for Cirrocumulus rankCirrocumulus
Apr 13, 2016
YOUR_HEADER_NAME would be whatever you name the header that the servers will be parsing out. As far as specifying the DNS server, I found this stating you don't have to specify one assuming your local resolver has been setup properly: "By default RESOLV::lookup queries the BIG-IP's local caching nameserver (bind) which you must configure in advance. If your RESOLV::lookup queries don't seem to work you should adjust your BIG-IP configuration as explained in f5 Solution Note SOL12224" I hope this helps and I hope it works for you.