Symptoms

When reusing a serverside TIME_WAIT connection, the BIG-IP system: -- Establishes the new connection if clientside/serverside connections are on the same TMM. -- Sends a RST 'Unable to obtain local port' if clientside/serverside connections are on different TMMs.

Impact

BIG-IP system behavior is inconsistent. In one case, BIG-IP establishes the connection. In the other case, BIG-IP resets the connection.

Conditions

This happens in two scenarios: Scenario 1: -- A new serverside connection is requested that matches an existing TIME_WAIT connection (e.g., by using source-port preserve-strict in the virtual server) -- Clientside/serverside connections are on the same TMM. Scenario 2: -- Clientside/serverside connections are on different TMMs.

Workaround

None.

Fix Information

BIG-IP system reuses serverside TIME_WAIT connections irrespective of clientside/serverside being on the same TMM/different TMMs.

Behavior Change