[nsp] Cisco 2500 Traffic Limit and high cpu utilization.

[Mehmet Ali Suzen]

On Mon, Mar 08, 2004 at 01:41:49PM -0500, Streiner, Justin wrote:
> On Mon, 8 Mar 2004, Mehmet Ali Suzen wrote:
> 
> > IOS version we are dealing is IOS version 12.1(20)
> > Interfaces consist of ethernet, serial and
> > group async. A LAN and dialups took gateway as this
> > router.  We have a large ACL on each interaface.
> > It works fine. In busy times out load gets significantly
> > high. I tried to enable ip cef, but it didn't work it out.
> 
> Is CEF still running?  Did you enable it on each interface?

When ever CEF has anabled (in 'conf term' ->'ip cef'), traffic blocked. 
Tho, I didn't try to enable cef globally, and all interfaces simultaneously.
Is is compulsory to do it or just global setting is sufficient?

> > What could went wrong? I will appriciate for any comment
> > or an idea.
> 
> I see that you're running NAT.  Do you have lots of traffic that gets
> NAT'd?  If you do a "show ip nat trans" you will see the NAT translations
> currently on the router.

NAT is there only. Nil. There is no traffic at all from NAT actually. 
We were planning to do so.
router1#show ip nat translations
 
router1#show ip nat statistics
Total active translations: 0 (0 static, 0 dynamic; 0 extended)
Outside interfaces:
  Serial0.1
Inside interfaces:
  Ethernet0
Hits: 0  Misses: 0
Expired translations: 0
Dynamic mappings:
-- Inside Source
access-list 10 interface Serial0.1 refcount 0

> 
> I brought this up because NAT, especially in large volumes, can really
> hit the CPU hard.  I think at least some NAT traffic ends up getting
> process-switched, but I'm not 100% sure about this.

I guess It implies that NAT is not an issue for my config.

-Mehmet