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davidy2001's avatar
Nov 07, 2022

Half ping VS cannot be successful

Hello, we have basic F5 config and diagram as below. When outside user 3725-1( ping the Virtual server, the half ping can be sucessful, and other ping is failed. In another word, we sent ping from 3725-1 ten times, each sending five ping packets, total 50 ping packets. The ping at 1, 3, 5, 7, and 9 are successful, while at 2,4,6,and 8 fail. The second picture below also show only the half ping are successful, and other fail. Is this configuration issue or something else such as bug etc? Thanks



4 Replies

  • davidy2001what happens if you perform a tcpdump on the eth1.1 interface of the active BIG-IP? The following is most likely what you need to capture this traffic and should be run on the active BIG-IP.

    tcpdump -nni internal host

    My guess is that the BIG-IP isn't persisting your ICMP request to the same destination which is why you are receiving partial loss of communication. If the tcpdump reflects that you might try the same test after implementing source IP persistence to the virtual server.

  • Hi davidy2001 , 
    > I think in this Case you have one of your routers down. 
    so open F5 cli and write this command " ping '' also " ping " your routers , to test reachability for both routers from F5 perspective first. 
    if your Ping gets reply from both of routers , we will troubleshoot for another workaround. 

    > Also , Send a snap shot from the pool that you put both of routers " , " and assigned it to 
    " virtual server ". 
    you will find it in ( local traffic , pools " select the routers pool I mean " , " , select members Tab ) 
    you should find view like this : 
    > Also try to ping from Router "" to " virtual server " 10 times as you did before. 
    and issue this command in Tmsh F5 cli " show sys connection cs-server-addr ". 
    send a snap shot from the command output , issue this command after ping directly after stopping ping from router ' do not exceed 5 seconds ' to find the output of active connections. 

    I hope this help you 

  • Paulius Please see below:

    Mohamed_Ahmed_Kansoh , I checked the two nodes, and both should be Ok. but I found other virtual servers do not have the issue. So it is this virtual server that has the issue. so replacing it would be fine. 

    Thank you all!


    • davidy2001 
      very well , it is a good news that you have gotten rid of your issue. 
      yes , if you have another virtual server works well , you can rebuild another new one with same configuration , it should work as expected.