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Remco's avatar
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Jan 16, 2012

Virtual sends [RST, ACK]





we recently replaced Cisco CSS by F5 BigIP, but we know have a problem in our production environment under load which we did not noticed in out acceptance environment.



We have a virtual configured and on this virtual we have an irules which does pool selection based on the requested uri.



What I see in the tcpdumps I took, is that on an existing tcp session there are several GET and POST requests where I can see the identical GET or POST message is also send to a poolmember as you would expect. But sometimes on an open client tcp connection we are getting a http GET or POST request and I do not see the request being send to a poolmember. I do see the F5 is first responding with a ACK and than ~5 seconds later a [RST, ACK] is send back to the client terminating the TCP session.


The uri requested should match on of uri's in the irules and I don't have any poolmembers down messages in the ltm log. Some of the pools are used in combination with SNAT automap, the uri with problems are mostly for pools without snat.



I have seen a couple of post reporting the same behaviour, but haven't seen a solution. Does anybody know what can cause this behaviour and how it can be solved?



The problem looks a similar as posted at:




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