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Vincent_95925's avatar
Vincent_95925
Icon for Nimbostratus rankNimbostratus
Mar 04, 2013

DIG command to a VIP used for DNS

Hi Guys,

 

I am pretty new to F5 and need some of your expert advice. We have set up 2 VIPs using same IP address on our LTM and are being used to load balance DNS servers, one running on UDP and one on TCP protocol. When i run dig @VIP_IP www.google.com, it doesnt work saying that it cannot connect to any server, but when i send the query in tcp by adding +tcp on the command, it works. Both VIP are UP and are using same pool.

 

Any Idea why? Is it normal?

 

TIA in advance! :D

 

 

basic
getting started
new to f5

1 Reply

  • nitass's avatar
    nitass
    Icon for Employee rankEmployee
    Mar 05, 2013
    have you tried to run tcpdump on bigip?

     

    tcpdump -nni 0.0 -s0 host x.x.x.x or host y.y.y.y and port 53

     

    or

     

    tcpdump -nni 0.0:nnn -s0 -w /var/tmp/output.pcap host x.x.x.x or host y.y.y.y and port 53

     

    x.x.x.x is virtual server ip

     

    y.y.y.y is pool member ip

     

     

    can you post the virtual server configuration?

     

    tmsh list ltm virtual (name)

     

    tmsh list ltm pool (name)