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George_Bab's avatar
George_Bab
Icon for Nimbostratus rankNimbostratus
Apr 09, 2021

After deleting pool members, traffic was still forwarded on them.

 

I had a Pool with 4 members and i deleted 2 of them . After that i was still seeing the traffic going towards the deleted pool members. Does anyone now why is that happening ?

 

Thanks,

G

application delivery
Deleted Members
LTM
members
persistance
pool

5 Replies

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  • SanjayP's avatar
    SanjayP
    Icon for Nacreous rankNacreous
    Apr 09, 2021

    This isn't possible at all. Are you see traffic going from client --> VIP --> pool where it was removed? Is it a web traffic from client or F5 health monitor traffic?

     

    • Check if those members are used in any other pool of a different VIP. Take tcpdump and analyse the traffic.
    • Check if you have any iRule/ltm policy on the VIP referening those members.
    • Check if you have synced the configuration after deleting if you have HA. It could be possible that standby F5 is sending health monitor traffic if config is not in sync

     

    • George_Bab's avatar
      George_Bab
      Icon for Nimbostratus rankNimbostratus
      Apr 12, 2021

      Hello Sanjay,

       

      Thank you for your answer. Yes i can see the traffic towards those 2 specific pool members that have already deleted. I have HA but the config is synced, no differences and also i have no iRules.

      Tried also to bounce the VIP but still the same.

       

      With the show sys connections also i can see the traffic going on those pool members.

  • Nikoolayy1's avatar
    Nikoolayy1
    Icon for MVP rankMVP
    Apr 10, 2021

    The servers could be members in another pool, there could a be health monitor on the nodes, they could be used in an iRule and so on?

     

    How did you determine that you still see traffic to the servers?

     

     

    Have you done show sys connection on the active F5 device for the VIP ip address that uses the pool with the removed members (don't do show sys connection without filters as it can cause issues)?

     

    https://support.f5.com/csp/article/K40033505

     

     

    I think you maybe think it is the same traffic but it is not as this is really rare the F5 device to have a corupt config and to need mcpd reload to clear it, so for now check everything else. You could use the network map to see where the server ip address and port are still used (also enable the option the irules to be searched):

     

     

    https://support.f5.com/csp/article/K20448153

    • George_Bab's avatar
      George_Bab
      Icon for Nimbostratus rankNimbostratus
      Apr 12, 2021

      Hello  ,

       

      Thank you for your answer. With show /sys connection i can see the traffic towards those 2 specific pool members. The VIP is configures without iRule or any persistance profile because that was my first thought also. The weird is that after the bouncing of the VIP the traffic is doing the same.

  • Nikoolayy1's avatar
    Nikoolayy1
    Icon for MVP rankMVP
    Apr 12, 2021

    Can you provide an output of the show sys connection ?

     

    Also you see from the GUI web interface that the pool members are removed ? If so check the CLI "tmsh show running-config" and see if the pool members are under the VIP, you may also check the config file "/config/bigip.conf" (if you have partitions there will be such file for each partition). If you the pool members to be removed from the GUI and bigip.conf but not the running config, do load sys config verify to see for errors. If there are no errors you may try mcpd reload for issues with a different config between the data plane and control plane:

     

    https://support.f5.com/csp/article/K13030

     

     

    If you still have issues after everything check the bug tracker, for example and maybe open a TAC case if you don't find anything in the bug tracker

     

    https://support.f5.com/csp/bug-tracker?sf189923893=1

     

     

    For first time I heard for such issue with the F5 device, so if you are right and not missing domethink obvious in the config (like checking the wrong VIP in another partition that has the deleted members, etc. ) as it is really strange.