Forum Discussion

hung_105573's avatar
Icon for Nimbostratus rankNimbostratus
Jan 22, 2013

How F5 handle session ?


hi all


i'm new F5 , i'm facing with concurrent session and how f5 handle session .


my diagram network : server farm--------FW--------F5--------internet


(Fw and F5 run mode route)


on F5 , i had config virtual server for access services from internet come server farm , and after time then concurrent session on FW grow


this is one of many virtual server on F5:


admin@wip(Active)(/Common)(tmos) show running-config ltm virtual Web_VNPT


ltm virtual Web_VNPT {


destination 222.x.y.z:http


ip-protocol tcp




pool Server_10.0.115.10_80


profiles {


tcp { }




vlans {










how to F5 handle session ? pls help me


thanks all



5 Replies

  • Hung, sorry but I'm not sure I understand the question. Could you re-phrase it please?
  • hi


    My mean is how the f5 process session access from internet come server inside ? when the session time out then F5 delete this session ?


    at the moment when it work about time then concurrent session on FireWall behind F5 grow hight . It make slow system network .


    pls help me


    thank all



  • Ahhh, OK, I think I get you now, thanks. So, you have an issue with the server side connections remaining idle for too long?



    So, the idle timeout is controlled by the TCP profile assigned to the Virtual Server. The default value is 300s/5mins which is fine in most cases. I'd suggest you create a custom profile with a lower timeout and assign it to the VS server-side only.



    Enabling the OneConnect feature should also help to reduce the number of server-side connections as it will re-use them.
  • Hi


    My F5 have many the virtual server , would you like tell me how to set onceConnect profile for all virtual server ? and if set then anything effect to system is working ?



    many thanks



  • OK, I'd suggest you read up on the OneConnect profile settings here: Create a custom OneConnect profile and apply it to each HTTP Virtual Server as required, default settings will probably be OK. I'd suggest you test first of course.



    There is of course always a bit of RAM and CPU overhead but hopefully this will be minimal, if you can even spot it.