Some dynamic translations stay in the translation table for
24 hours. Clearing dynamic NAT translations from the translation table before
they timeout is possible by using the clear ip nat translation
* command. This is particularly useful when testing NAT configuration.
Static NAT entries are immediately reestablished in the table.
Additional options exist for clearing only part of the table.
Use the clear ip nat translation ? feature,
Changing the NAT Default Inactivity Timeout Timers
TCP translations inactivity timeout defaults to 24 hours,
unless an RST or FIN bit packet is seen on the stream, in which case they
timeout in one minute. To change the amount of time after which NAT translations
timeout, use the global configuration ip nat translation
command. To disable the timeout, use the no form of this command.
Rtr1(config)#ip nat translation timeout seconds
Rtr1(config)#no ip nat
Applies to dynamic translations, except for overload (PAT)
translations. Default is 86,400 seconds (24 hours).
Seconds after which the specified port translation times
The following example demonstrates changing the NAT default
timeout value to 120 seconds on Rtr1.
Rtr1(confif)#ip nat translation timeout 120
Additional timer options are covered in the overload (PAT)