RE: router CPU usage?

  • To: "'William Wong'" <wwong at hkt dot net>, "'David R. Conrad'" <davidc at apnic dot net>
  • Subject: RE: router CPU usage?
  • From: Barry Raveendran Greene <bgreene at cisco dot com>
  • Date: Sat, 10 May 1997 17:17:40 +0800
  • Cc: "'apops at apnic dot net'" <apops at apnic dot net>
  • Encoding: 95 TEXT
  • Sender: owner-apops@apnic.net
    • Hello All,
      
      First, if your CPU is high and your running full routes, you need to 
      understand _what_ is causing the high CPU before jumping on a BGP issue. 
      Check the "show proc cpu" command to see what process is consumimg the 
      resources. Some times it is not BGP but the "ip input" process. If yes, 
      then add the following to all of your interfaces:
      
      	no ip redirects
       	no ip directed-broadcast
       	no ip proxy-arp
      
      On the FDDI, ethernet, and other LAN interfaces, add (in addition to the 
      above):
      	
      	ip route-cache same-interface
      
      If usually takes care of the high "ip input" problem.
      
      Another common "high cpu" issue with router is too many SNMP queries. This 
      will also show up with the "show proc cpu" command.
      
      Barry
      
      > From:    William Wong [SMTP:wwong at hkt dot net]
      > To:      David R. Conrad
      > Date:    97-05-09 18:01:29
      > Subject: Re: router CPU usage?
      >
      > Normal CPU usage is not too hard but when there is a route flap or a BGP
      > reset, it can go up as high as 99% on our 7000 for a while but on the
      > 75xx, the high CPU usage won't substain as long.
      >
      > william
      >
      >  On Fri, 9 May 1997, David R. Conrad wrote:
      >
      > > Hi,
      > >
      > > A very informal survey...
      > >
      > > Out of curiosity, of those ISPs who are running with full tables out
      > > there, can you tell me how hard your routers are working (e.g., % CPU
      > > utilization) and what kind of routers they are?
      > >
      > > To start: APNIC has a PC Unix box for a router (Pentium 100 Mhz, 64 MB
      > > memory, FDDI connection to NSPIXP-2) and CPU load of the gated process
      > > is around 0.05% (22 MByte memory image -- I'm seeing around 48K
      > > routes).  Of course, since we aren't switching too many packets,
      > > APNIC's info isn't particularly relevant...
      > >
      > > This is purely for informational purposes -- please send me mail and
      > > I'll summarize (or keep confidential if you'd prefer)...
      > >
      > > Thanks,
      > > -drc
      > > 
      _________________________________________________________________________
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      > > 
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      > >
      >
      > 
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      -----
      > William Wong                          		Phone    : (852) 2883-7866
      > Internet Provisioning                   	Fax      : (852) 2962-5005
      > Hongkong Telecom		 		Email	 : wwong at hkt dot net
      >                                                 URL      : 
      http://www.hkt.net
      >
      >
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      --
      --
      --
      Barry Raveendran Greene             |       ||        ||        |
      Senior Consultant                   |       ||        ||        |
      Consulting Engineering              |      ||||      ||||       |
      tel: +65 738-5535 ext 235           |  ..:||||||:..:||||||:..   |
      e-mail: bgreene at cisco dot com           |  c i s c o S y s t e m s  |
      
      --
      --
      --
      Barry Raveendran Greene             |       ||        ||        |
      Senior Consultant                   |       ||        ||        |
      Consulting Engineering              |      ||||      ||||       |
      tel: +65 738-5535 ext 235           |  ..:||||||:..:||||||:..   |
      e-mail: bgreene at cisco dot com           |  c i s c o S y s t e m s  |
      
      _________________________________________________________________________
      To unsubscribe: send "unsubscribe" to apops-request at apnic dot net
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