CCIE Practical Studies, Volume I

Clearing and Changing NAT Translations

NAT TCP translations will time out after a default of 24 hours. You can change the timeout values on a per-protocol basis with the following commands:

• ip nat translation timeout seconds ” Specifies the timeout value that applies to dynamic translation, except for ones with overload translations. The default is 86,400 seconds, or 24 hours.

• ip nat translation udp-timeout seconds ” Specifies the timeout value of UDP translations. The default is 300 seconds, or 5 minutes.

• ip nat translation dns-timeout seconds ” Specifies the timeout value for DNS. The default is 60 seconds.

• ip nat translation tcp-timeout seconds ” Specifies the TCP timeout values. The default is 86,400 seconds or 24 hours.

• ip nat translation finrst-timeout seconds ” Specifies the timeout for NAT TCP flows after a FIN or RST bit is set in the TCP header. The default is 60 seconds.

• ip nat translation icmp-timeout seconds ” Specifies the timeout for NAT ICMP packets. The default is 60 seconds.

• ip nat translation port-timeout [tcp udp] port_number seconds ” Specifies the timeout value for specific TCP or UDP port numbers .

• ip nat translation syn-timeout ” Specifies the timeout value for NAT TCP flows after the SYN bit is set, and gives no further data.

To clear NAT translations or statistics, use the following commands:

• clear ip nat translations [ *inside inside_address outside outside_address tcp port_number udp port_number ]

• clear ip nat statistics