Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. If you'd prefer to explore, try our test area to get started. And see here for current known issues.

New Member

NPE-G1 and PAT performance

We have used Cisco7206VXR as a perimeter router. Main feature is address translation for a big private network. NAT overload (PAT) is used with a pool of 128 public addresses.

The problem is a performance. When nat table contains about 20 000 sessions and cumulative traffic is 1 500 pps CPU load is 100%! There is nothing “special” in the configuration.

Personally I would expect higher performance with 7206VXR with NPE-G1 and IOS 12.3-5a.

Do you use a similar design and what is your experience?


Re: NPE-G1 and PAT performance

The high CPU problem you are experiencing maybe the result of a software bug. However also note that each NAT translation consumes about 160 bytes in DRAM. Thus you need to check if your router has more than enough memory to support thousands of NAT translations. Performance improvements are typically made via configuration changes, so also check your configuration and remove unwanted configuration steps. You could also refer to the following document for tips.