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hoonsong_37003's avatar
hoonsong_37003
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Aug 28, 2012

Only 1 Pool Member Can Ping Out At Any One Time

I have a pool with 2 members and I am trying to ICMP ping to an external server (Server A) residing on a different subnet from my members. Only one of the members can ping Server A at any one time. And it alternates between the 2 members usually in between periods of inactivity. This problem goes away if I have only one member in the pool.

 

I notice the member that can ping out to Server A is usually the one in the F5 connection table that receives all traffic from Server A. I suspect it has something to do with the ICMP replies not going to the originating pinging member. A tcpdump reveals returning ICMP replies are alternating between the 2 members in a ICMP fail test case. Whereas in a ICMP successful test case, the ICMP replies do not alternate and all go to the originating ping member.

 

I have seen other F5 setups that have no such issue. Both members can ping Server A at the same time. All ICMP replies go to the originating pinging member.

 

Is there something wrong with my F5 setup? Any help will be appreciated! Thanks =)

 

 

config
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  • hoonsong_37003's avatar
    hoonsong_37003
    Icon for Nimbostratus rankNimbostratus
    Aug 29, 2012
    I have resolved the u/m issue. Now both members can ping to server A at the same time. I changed a setting in the local F5 configuration for my ip forwarding virtual server under client profile. I changed it from route_friendly_fastL4 to fastL4 for my ip forwarding virtual server between skip and external interface. Am still looking at what is the difference between the 2 settings... but if anyone knows pls let me know.

     

  • hoonsong_37003's avatar
    hoonsong_37003
    Icon for Nimbostratus rankNimbostratus
    Aug 29, 2012
    route_friendly_fastL4 is a custom fastL4 profile the following are the difference in their settings:

     

     

    default fastL4 profile:

     

    1. Reset on Timeout is Disabled

     

    2. Idle Timeout is set to 300

     

    3. Loose Initiation is Disabled

     

    4. Loose Close is Disabled

     

     

    custom route_friendly_fastL4 profile:

     

    1. Reset on Timeout is Enabled

     

    2. Idle Timeout is set to Immediate

     

    3. Loose Initiation is Enabled

     

    4. Loose Close is Enabled

     

     

    Anyone can tell me why the custom route_friendly_fastL4 is causing ICMP ping to not return to the originating requestor?