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Prince's avatar
Prince
Icon for Altostratus rankAltostratus
Aug 25, 2016

F5 Not able to communicate to Backend Server

Hello Experts, I am observing a very strange issue on F5. This setup is basically SSL termination on F5. Configuration Details: VIP with SNAT-automap. Source and Backend Servers are in Same Subnet Backend is not handling SSL connections

 

When took packet capture I see SSL handshake getting completed fine between client and VIP but the moment Client Sends Application Data, F5 initiates a SYN packet to backend server on wrong port (443) while it is actually listening on 9000 port. Since server is not listening on 443, it sends a RST and then the same RST is being sent to client. NOTE: There are none other pools with same server on port 443

 

Any advise on this ? Am i missing any specific configuration ?

 

I am using 11.5.3 HF2

 

Thanks in advance,

 

application delivery
LTM

2 Replies

  • Jinshu's avatar
    Jinshu
    Icon for Cirrus rankCirrus
    Aug 25, 2016

    Hi Prince,

     

    What is the Pool Configuration? Can you paste the config here?

     

    -Jinshu

     

  • Stanislas_Piro2's avatar
    Stanislas_Piro2
    Icon for Cumulonimbus rankCumulonimbus
    Aug 25, 2016

    Hi,

     

    did you create the VS with port 0 before defining the VS port?

     

    When the VS is created without port number, the parameter "translate port" is disabled. enable it on the VS (Advanced view)