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wtwagon_99154's avatar
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Jan 26, 2011

fastl4 profile - always reaching idle timeout value on persistent data stream



We are running into an issue where we have an IP Forward Virtual Address , and the traffic passing through this Address always seems to reach the idle timeout threshold.




Configuration of the L4 profile is:




Unchecked - Reset on Timeout


Idle Timeout - 3600 seconds


Loose Initiation / Lose Close - Checked




Everything else default




The TCP traffic we having passing through this F5 is connecting to a data feed, where it will be receiving streamed data every few minutes. However, even if there is traffic passing at that exact moment, the F5 always seems to dump the connection after 1 hour.




My thoughts were to add a TCP Keep-Alive Interval, but I could not find anything for it in the fastl4 profile's help section. I found one on Ask F5, but it does not apply to the version I am at:




I am on version 10.2.




Anyways, we get around this by setting the idle timeout to 24 hours. However, I was wondering why the F5 was detecting this as an idle connection when it is not.








8 Replies

  • Yeah, we can definitely confirm that there is data passing during that time frame. It's like it doesn't even matter and closes the connection anyways as soon as the idle timeout is reached.



    The servers initiating the traffic have the F5 as the default gateway, and then a Cisco router, and then the server sending the data.



    There are keep-alive settings in the FastL4 profile, but no description in the help menu. Wasn't sure if it could be applied there still, since the option is there.
  • Didn't even notice the keep-alive setting hidden away at the bottom of the profile.



    Are you using SNAT on the Virtual Server?
  • Nope, no SNAT on the F5 whatsoever.



    Just a couple other items:



    1) I thought it was perhaps the reset on timeout originally - and removed it - to no avail. If I set it to 5 minutes, I'm disconnected after 5 minutes.



    2) If I bypass the F5 - the stream stays open the entire time.



    3) There's a tiny amount of connections using this IP forwarder, so I am not concerned about the loose init / close.
  • And both the server's request and the data feed's response traverse the F5, right?
  • I'd make a support case with F5 and see what their thoughts are. If I come up with something else, I'll post.
  • I'm having the same exact issue, any feedback/solution for this ticket. Thank you
  • I've tested and seen keepalives work as expected with a standard FastL4 profile and a TCP profile VS in 10.2.1. However, if you have loose initiation and(/or?) loose close enabled with keepalives on a FastL4 profile , no keepalives will be sent by TMM. I think this is because TMM isn't tracking the connection as it would if the "loose" options are disabled.



    If the issue isn't with keepalives, but with TMM closing the connection I suggest opening a case with F5 Support to diagnose the issue. If you do so, can you reply back with what you figure out for future reference?