Forum Discussion

Kenneth1234's avatar
Icon for Nimbostratus rankNimbostratus
Nov 16, 2021

Lost 1 packet when Query F5 LTM

Hi.. We have setup a virtual Server to load balance 3 Windows DNS servers in LTM(implemented with route domain). We used iapp DNS template to configure from BigIP side, all seems ok. But when we try to resolve any address with nslookup we are getting DNS Request Timed out error. After the first time out, we are able connect to that VIP and able to resolve the host names.




DNS request timeout

timeout was 2 seconds

Default Server: Unknown




Server: UnKnown



Non-authoritative answer:






Pinging with 32 bytes of data:

Reply from bytes=32 time=48ms TTL=51  

Reply from bytes=32 time=48ms TTL=51

Reply from bytes=32 time=48ms TTL=51

Reply from bytes=32 time=48ms TTL=51


Ping statistics for

  Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),

Approximate round trip times in milli-seconds:

  Minimum = 46ms, Maximum = 50ms, Average = 48ms

1 Reply

  • Hamish's avatar
    Icon for Cirrocumulus rankCirrocumulus

    You need to perform some diags. What can you prove?


    What do you see on a tcpdump at the BigIP? Do you see the first request come in to the VIP? Do you see that request being passed? Do you see the request make it to the back end server? And do you see the responses? Where do they go?


    There's no magic bullet (Unless someone gets lucky in guessing).