Explanation of UIB and UIOB

Unanswered Question
Nov 9th, 2007
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We are having PIX 535 and we are trying to debug an application level problem this application access the servers which are behind PIX.

output of sho conn detial ( ip address )

shows two connections one in UIB state and other UIOB state. Primarily it is straight to decipher the output.

If one conncetion on one port is only in UIB mode and one connection is UIOB mode what does it mean exactly ? Is it that one UIB connection is only getting incoming data and no data is replied back but TCP connection is extablished. That means it is a valid connection. On the other hand if connection is UIOB : data is coming and also replied back to requester ( client ) is my understanding correct ?

any link for more detailed explanation on connection on cisco.com ?

Thanx in advance ?


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Overall Rating: 5 (2 ratings)

Hi Subodh

The "U", "I", and "O" flags denote that the connection is active and has received inbound and outbound data. The "B" flag, the connection is initiated from the outside. Are you able to say what the problem is?

U - up

I - inbound data

O - outbound data,

B - initial SYN from outside

Please rate if this helps,



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