Policy Routing Performance Impact

[kfarrington]

Hello,

I have a router that is passing traffic between two corporate networks at the rate of about 2M/bit per sec. I would like to implement policy routing on this routing device (4700) with 32MB of mem, 1 ethernet and two FDDIs.

I would have to apply the following:-

E0

ip policy route-map encryp-route-back

The problem is that only 0.001 % of the traffic needs to be policy routed and I am worried about implementing this as all the traffic needs to check the route-maps and be policy routed when only a very small number of packets require the next hop change.

We also have an externded acl on this interface already.

Should I be concerned about this?

Thx

[sbilgi]

When you implement policy routing all packets coming into the interface will be process switched so policy routing can have an impact on performance for that reason.

Policy-based-routing itself does not affect much performance of the router, but packet forwarding does.

Policy-Based Routing is supported in fast-switching path so the performance impact is minimized.

To activate fast-switching, you need to enable 'ip route-cache policy' on the same interface, where you apply the route-map.

Also, it would be better to keep as few lines in ACL as possible. The shorter ACL is - the less CPU is required to match the packets.