Cisco Support Community
Community Member

NAT translations

Hi, I don't know if I have found a direct correlation but every time I clear "ip nat translation *" the internet connection seems to be way faster. I have PAT "overload" setup on the interface to the internet. The interface is pretty much maxed out all the time but when I clear the translations the web pages come up much faster. I checked the memory and only about 5% of memory is being used the whole time. The IOS version is c2800nm-advipservicesk9-mz.124-3b.bin. I did some speed tests. I get like 160K or so of bandwidth. Once I clear the translations I receive aroud 1M of bandwidth on the T1. Does anyone know what might be the issue?

Community Member

Re: NAT translations

I would imagine that it doesnt stay fast for very long. What may be happening is that it has to look through the table for the proper entry and as the table grows larger and the connections increase you slow down. This of course is dependent on how many users and what applications they are using. Can you create a NAT pool of different outside addresses instead of overloading the one address?

Community Member

Re: NAT translations

No can't really do that. But I just realized that I have policy based routing configured that is directing the workstation traffic to the internet. So I think that CEF doesn't work with PBR. Is there any correlation between CEF and PAT?

Hall of Fame Super Gold

Re: NAT translations

You might be running into CSCsj08002. Better upgrade IOS to latest 12.4 mainline in your case.

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