This behavior is documented in Cisco bug ID CSCdy58717.
TCP/UDP connections do not time out. This prevents translation (xlate) entries from timing out as well. Issue these commands in order to check whether connections do not time out:
- show connection count Shows a large number of connections.
- show timeout Shows the idle timeout value.
The connection timeout value must not be larger than the timeout value for the idle connections.
As a workaround, perform either of these two tasks:
- If this condition takes a long time to develop, then reload the PIX.
For example, this workaround is appropriate if this issue only occurs several weeks after the PIX reloads.
- If this condition takes a shorter time to develop, then issue the clear xlate command.
This workaround is appropriate if this issue occurs only a couple of days after PIX reloads, or if a frequent reload is not a feasible workaround.
If the clear xlate command does not clear all non-timing out connections, issue the clear local-host command.
As an alternative, download and upgrade the software version to the latest available version.