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RE: High Processor Rates on Routers.
I have seen similar behavior like this, on various platforms (3640, 7206 and 7513) when using PBR (Policy Based Routing) on an interface looking at source IP's to make a routing decision. The BGP SCANNER process jumps up to 99% for a second or 2 every 60 seconds. After taking out the POLICY MAP's on the appropriate interfaces, the BGP SCANNER processes never jump up again. I never really found out why this happened from Cisco, TAC stated that most routers do not have specialized ASIC's to handle PBR, and so it is handled like a generic CPU process, and if your BGP table is large, and it has to walk the BGP TABLE often (if you receive large amounts of updates etc...), and PBR is enabled, weird things happen... Hope this helps... -Aaron -----Original Message----- From: firstname.lastname@example.org [mailto:email@example.com]On Behalf Of Chris Roberts Sent: Wednesday, November 06, 2002 8:54 AM To: firstname.lastname@example.org Cc: email@example.com; firstname.lastname@example.org Subject: Re: High Processor Rates on Routers. On Wed, Nov 06, 2002 at 08:21:39AM -0500, email@example.com wrote: > > > Ladies & Gentleman. > > > Was wondering if it is common for processor rates on higher end Crisco boxes to race from 1 or 2 % show on the 5 second processor rate interval, to anywhere from 70 to 90 %, instanteously, then drop back down to 1 or 2 % after 10 seconds. > > Check out for down interfaces, Serial/POS on the router. I've seen this cause these spikes (although not normal for 10 seconds, more normally about a second or so) every 30 seconds and make sure they're shut down. Also check out OSPF to see if there is an interface flapping somewhere in your network with the undocumented command 'sh ip ospf stat', which will tell you what OSPF is doing, and look for a correlation between the delta times and your high CPU utilisation. BGP can cause a lot of processor utilisation when updates are received, although this is not normally at accurate 30 second intervals, so I wouldn't suspect this particularly. Cheers, -- |=========----- -------=======| | Chris Roberts (firstname.lastname@example.org) | |=======------- -----=========|