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gautier2310_360's avatar
gautier2310_360
Icon for Nimbostratus rankNimbostratus
May 03, 2018

Modify VS port 80 to 8080

Hello,

 

My pool is configured on port 80. I'm trying to modify my port on my virtual server but it's doesn't work. When my VS is configured with port 80 it's works, after I modify the port to 8080 it's doesn't work. Port translation is ticked in any case.

 

In resume : OK : Client --> VIP 80 --> Server 80 KO : Client --> VIP 8080 --> Serveur 80

 

If i do tcpdump (with VS on port 8080), F5 receive the syn, but never replies back.

 

Do you have some ideas ?

 

BIG-IP
security
virtual server
  • youssef1's avatar
    youssef1
    Icon for Cumulonimbus rankCumulonimbus
    May 03, 2018

    Hello,

    Are you sure that you don't have an "absolute link" in your application that redirect user on port 80. After you try to reach it in port 8080...

    Set your Vs port to 8080 and stick this following irule then check logs in cli:

    tailf /var/log/ltm

    when HTTP_REQUEST {
   set LogString " Client [IP::client_addr]:[TCP::client_port] -> [HTTP::host][HTTP::uri]"
   log local0. " ============================================="
   log local0. " $LogString (request)"
   foreach aHeader [HTTP::header names] {
      log local0. " $aHeader: [HTTP::header value $aHeader]"
   }
   log local0. " ============================================="

}

when HTTP_RESPONSE {
   log local0. " ============================================="
   log local0. " $LogString (response) - status: [HTTP::status]"
   foreach aHeader [HTTP::header names] {
      log local0. " $aHeader: [HTTP::header value $aHeader]"
   }
   log local0. " ============================================="   

}

    This Irule will help you to log all your header and will help us to find/identify the problematic.

    let me now about logs....

    Regards,

  • gautier2310_360's avatar
    gautier2310_360
    Icon for Nimbostratus rankNimbostratus
    May 03, 2018

    This is the output tcpdump command :

     

    08:38:59.389677 IP CLIENTIP.55311 > VSIP.webcache: S 1991629810:1991629810(0) win 14600

     

    08:38:59.392421 IP CLIENTIP.55311 > VSIP.webcache: S 1991629810:1991629810(0) win 14600

     

    08:39:00.389053 IP CLIENTIP.55311 > VSIP.webcache: S 1991629810:1991629810(0) win 14600

     

    08:39:00.392239 IP CLIENTIP.55311 > VSIP.webcache: S 1991629810:1991629810(0) win 14600

     

    08:39:02.388742 IP CLIENTIP.55311 > VSIP.webcache: S 1991629810:1991629810(0) win 14600

     

    08:39:02.391842 IP CLIENTIP.55311 > VSIP.webcache: S 1991629810:1991629810(0) win 14600

     

    No syn ack from F5

     

  • Snipetech's avatar
    Snipetech
    Icon for Nimbostratus rankNimbostratus
    May 04, 2018

    make sure your firewall(if there is one) upstream is not blocking traffic. Also, did you set the vip as layer 7 or layer 4?