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Sandeep_374170's avatar
Sandeep_374170
Icon for Nimbostratus rankNimbostratus
Oct 16, 2018

F5 says application server node down: icmp monitoring fails

Hi,

 

We are using F5 version BIG-IP 11.6.1 Build 0.0.317 Final. Everything was working fine but suddenly on Friday the application client were not able to connect with application server. When I checked the Node status in F5 it was down however all the application server nodes were UP. Log says "Oct 12 18:38:54 tb2f5001 notice mcpd[9239]: 01070640:5: Node /Common/TB2SME012 address 10.1.130.70 monitor status down. [ /Common/icmp: down ] [ was up for 2742hrs:57mins:59sec ]". On tcpdump I don't see any icmp packets sent to application server. After removing the icmp monitoring now application client is able to connect to application server BUT when I again added monitoring as icmp it says cheking but I dodn't see any icmp packet in tcpdump.

 

/Sandeep

 

application delivery
BIG-IP

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  • F5_Learner_3295's avatar
    F5_Learner_3295
    Icon for Nimbostratus rankNimbostratus
    Oct 16, 2018
    Hi,

1.After removing the icmp monitoring now application client is able to connect to application server - **Can you confirm which monitor you are using when the icmp was removed.**

2.can you paste the tcpdump command which you used to check the icmp packets.

Regards
    • Sandeep_374170's avatar
      Sandeep_374170
      Icon for Nimbostratus rankNimbostratus
      Oct 16, 2018

      Hi,

       

      Please find my answer inline

       

      1.After removing the icmp monitoring now application client is able to connect to application server - Can you confirm which monitor you are using when the icmp was removed. [Sandeep]: No monitor, the status it shows "Unknown (Enabled) - Node address does not have service checking enabled"

       

      2.can you paste the tcpdump command which you used to check the icmp packets. [Sandeep]: tcpdump -i Service -i Admin host 10.1.130.70 -s 0 -XX For manual ping I can see the traces were captured. I mean from terminal when I execute "ping 10.1.130.70 -I Service"

       

      /Sandeep

       

    • F5_Learner_3295's avatar
      F5_Learner_3295
      Icon for Nimbostratus rankNimbostratus
      Oct 16, 2018

      Hi, what monitor is configured on node ? -Default ??

       

      what monitored is configured on pool ?

       

      Regards

       

    • Sandeep_374170's avatar
      Sandeep_374170
      Icon for Nimbostratus rankNimbostratus
      Oct 16, 2018

      Hi,

       

      what monitor is configured on node ? -Default ??

       

      [Sandeep]: Yes, Node Default

       

      what monitored is configured on pool ?

       

      gateway_icmp