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IOS NAT - how long do NAT translations live?

mmedwid
Participant
Participant

When I run a "show ip nat translations" I get a table of traffic that's been NATTED and to where that traffic was headed. The question I have is - how long do these translations live before they expire?

1 ACCEPTED SOLUTION

Accepted Solutions

Only active ones.

If you look in the note is says TCP sessions that see a FIN or RST are 1 minute. So if they are closed they will be cleared in 1 minute.

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4 REPLIES 4

tdrais
Rising star
Rising star

It looks like TCP is actually set to default to 24 hours:

http://www.ciscopress.com/articles/article.asp?p=25273&seqNum=5

..and your article confirms that.

I found the verbose switch on the command "show ip nat trans" and that confirmed the 24 hours of persistence in the table.

Only active ones.

If you look in the note is says TCP sessions that see a FIN or RST are 1 minute. So if they are closed they will be cleared in 1 minute.

Thank-you - great point.

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