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Anesh's avatar
Anesh
Icon for Cirrostratus rankCirrostratus
May 08, 2014

TCP keep Alive Reset

I have a F5 LTM VIP with the below config

 

Vitrual test{ destination 6.6.6.6:9041 ip-protocol tcp persist { source_addr{ default yes} } pool test profiles{ test_9041{} } snat automap }

 

ltm profile tcp test_9041{ app-service noce defaults from tcp-lan-optimized keep-alive-interval 60 }

 

When i telnet to the above VIP, the connection is reset after 60 seconds, this started happening soon after i implemented the keep alive interval for 60 seconds

 

The Question is why is the connection reset after 60 seconds, even though the idle-time-out setting is default for 300 seconds So ideally the telnet connection should be reset only after 300 seconds, correct??

 

application delivery
deployment
design
LTM

6 Replies

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  • Cory_50405's avatar
    Cory_50405
    Icon for Noctilucent rankNoctilucent
    May 08, 2014

    Correct, unless your server is resetting the connection. Can you do a packet capture on the server side and see if the server is sending the reset?

     

  • Anesh's avatar
    Anesh
    Icon for Cirrostratus rankCirrostratus
    May 08, 2014

    I forgot to mention I am doing a telnet to a https port. Is it because the port expects a ssl handshake??

     

  • Cory_50405's avatar
    Cory_50405
    Icon for Noctilucent rankNoctilucent
    May 08, 2014

    Correct. You are encountering the SSL handshake timeout. You can modify it however you see fit:

     

    http://support.f5.com/kb/en-us/solutions/public/13000/800/sol13834.html

     

  • Anesh's avatar
    Anesh
    Icon for Cirrostratus rankCirrostratus
    May 08, 2014

    But this VIP is SSL passthrough and does not use any SSL profiles

     

  • PK_Bhatia's avatar
    PK_Bhatia
    Icon for Nimbostratus rankNimbostratus
    May 08, 2014

    I am not sure if you tried persistence profile or not, if not you may try looking into it.

     

  • Anesh's avatar
    Anesh
    Icon for Cirrostratus rankCirrostratus
    May 09, 2014

    I am using source ip persistence, and i dont think it is a persistence issue, since i see the record in the persistence table even after the connection is removed from the connection table after 60 seconds.