[c-nsp] Arp Input Process Causing Spike in CPU

[Rodney Dunn]

What type of box? 75xx?

What code?


We have done a new scalability rewrite of the ARP code to get thousands
of entries. I need to check where that is going in.

Rodney



On Thu, Mar 15, 2007 at 10:40:22AM -0400, Christian Koch wrote:
> This is an NSP network.. All the arp entries are customers
> 
> Also log errors
> 
> Mar 15 07:38:35: %SYS-3-CPUHOG: Task ran for 6072 msec (72/20), process
> = ARP Input, PC = 4025C948.
> -Traceback= 4025C950 403CA9A0 4024340C 402433F8
> Mar 15 07:39:13: %FIB-2-FIBDOWN: CEF has been disabled due to a low
> memory condition.
>  It can be re-enabled by configuring "ip cef [distributed]"
> edge1-gw1.SJC1#
> 
> 
> 
> -Christian 
> 
> |-----Original Message-----
> |From: Gert Doering [mailto:gert at greenie.muc.de] 
> |Sent: Thursday, March 15, 2007 10:38 AM
> |To: Christian Koch
> |Cc: cisco-nsp at puck.nether.net
> |Subject: Re: [c-nsp] Arp Input Process Causing Spike in CPU
> |
> |Hi,
> |
> |On Thu, Mar 15, 2007 at 09:44:23AM -0400, Christian Koch wrote:
> |> I'm seeing cpu spikes due to  the arp input process running high ..
> |> 
> |> Currently every route is pointed to next hop and the arp table looks 
> |> like..
> |> 
> |> #sh ip arp sum
> |> 1743 IP ARP entries, with 21 of them incomplete
> |
> |1743 ARP entries?
> |
> |Over *thousand seven hundred* entries?  What sort of networks 
> |have you connected to this router...?
> |
> |> Can anyone suggest how to reduce this for a short term fix... I know 
> |> the long term is to upgrade the mem
> |
> |Memory doesn't play a role in this.  Topology does, 
> |reasonably-sized subnets, CoPP rate-limiting ARP storms, etc.
> |
> |gert
> |--
> |USENET is *not* the non-clickable part of WWW!
> |                                                           
> |//www.muc.de/~gert/
> |Gert Doering - Munich, Germany                             
> |gert at greenie.muc.de
> |fax: +49-89-35655025                        
> |gert at net.informatik.tu-muenchen.de
> |
> |
> 
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