[nsp] High CPU utilization from traffic with no destination interface?

[Ejay Hire]

They go all the way up to the cpu before being dropped and a destination host/network unreachable ICMP message is generated.  One of the advantages of Full-table BGP on Core routers is the ability to set a default route to null.

-----Original Message-----
From: Temkin, David [mailto:temkin at sig.com]
Sent: Thursday, June 26, 2003 1:19 PM
To: cisco-nsp at puck.nether.net
Subject: [nsp] High CPU utilization from traffic with no destination
interface?


Does anyone know the actual IOS architecture for handling packets that enter
the router where the router doesn't have a route for them?

I had a situation where a large amount of traffic was directed at one of my
routers that didn't have a route to the destination and the CPU was pegged
at 99%...  When I added an ACL blocking traffic to the networks that I
didn't have routes to, the utilization dropped dramatically.

Thanks,

-Dave


David Temkin
S-I-G
401 City Avenue
Bala Cynwyd, PA 19004
http://www.sig.com <http://www.sig.com> 



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