[cisco-bba] need help on troubleshooting high cpu on 7206NPE300 LNS

Oliver Boehmer (oboehmer) oboehmer at cisco.com
Thu Jan 25 04:13:20 EST 2007


Arie,
 
encapsulating/decapsulating L2TP packets should not happen in IP Input
process, this is done in the interrupt path
 
Anthony: Something is preventing your interfaces from
interrupt-switching the traffic. Another possibility is packet
re-assembly (which would be shown in "show ip traffic", as Paul just
suggested). Do a "clear counter" and then check "show int stat" which
interface(s) send the majority of pkts in the process path. Are still
users connected which received a framed-compression attribute before you
made the change?
 
    oli


________________________________

	From: cisco-bba-bounces at puck.nether.net
[mailto:cisco-bba-bounces at puck.nether.net] On Behalf Of Arie Vayner
	Sent: Thursday, January 25, 2007 8:38 AM
	To: Anthony Law; cisco-bba at puck.nether.net
	Subject: Re: [cisco-bba] need help on troubleshooting high cpu
on 7206NPE300 LNS
	
	


	On 1/25/07, Arie Vayner <ariev at vayner.net> wrote: 

		Anthony,
		
		The high CPU on IP Input is normal, as this is where the
L2TP work is being done.
		Also note that you have a high rate of CPU being used in
Interrupts (91%/44% means that 44% is used for Interrupts). Interrupts
on Cisco routers are usually linked directly to a high rate of traffic
(on centralized CPU devices). 
		I would assume you box is very close to its limit of how
much traffic it can handle. Could you please send some of the "show
interface" outputs (for the FastEthernet/GigE/ATM ports you might have).
This would allow us to get a better estimation. 
		
		You need to take into account that this is a centralized
CPU platform, and all traffic is handled by the CPU. This means that the
scale factor is not only a question of how many sessions you have
concurrently, but also how much traffic (mostly in PPS and not BPS) they
transmit. 
		
		Thanks
		Arie 
		
		
		
		On 1/25/07, Anthony Law < antnada at hotmail.com
<mailto:antnada at hotmail.com> > wrote: 


			Dear all
			 
			Thank you for all of your input. I configured
vpdn ip udp ignore checksum
			& I have corrected a mis-config on our radius
server (passing compression attribute to cisco) now that the L2TP data
daemon is running normal, but I am still facing high cpu on Pool Manager
& IP Input
			anymore suggestions?
			 
			 
			CPU utilization for five seconds: 91%/44%; one
minute: 91%; five minutes: 86%
			 PID Runtime(ms)   Invoked      uSecs   5Sec
1Min   5Min TTY Process 
			   1           4       175         22  0.00%
0.00%  0.00%   0 Chunk Manager    
			   2      487964   5014024         97  0.00%
0.00%  0.00%   0 Load Meter       
			   3     1606476    870141       1846  0.00%
0.00%  0.00%   0 CEF Scanner      
			   4    22428792   3318958       6757  0.00%
0.06%   0.05%   0 Check heaps      
			   5   481842360 102963163       4679  9.05%
9.70%  7.90%   0 Pool Manager     
			  37  11275060121049358292       1074 36.02%
35.07% 32.40%   0 IP Input 
			
			Thank You
			 
			Anthony
			
			
			
			
________________________________


			> Date: Wed, 24 Jan 2007 02:37:10 +0200
			> From: nitzan.tzelniker at gmail.com
			> To: antnada at hotmail.com
			> Subject: Re: [cisco-bba] need help on
troubleshooting high cpu on 7206 NPE300 LNS
			> CC: cisco-bba at puck.nether.net
			> 
			> You can try
			> 
			> vpdn ip udp ignore checksum
			> 
			> Nitzan
			> 
			> On 1/24/07, Anthony Law < antnada at hotmail.com
<mailto:antnada at hotmail.com> > wrote:
			> > Dear all,
			> >
			> > We have a 7206 w/NPE300 running as a LNS
terminating pppoe sessions from our
			> > telco. We are concurrently running around
360 pppoe sessions. 
			> >
			> > Recently. I noticed that our 7206 is having
extremely high cpu, at times
			> > going to 100%, please see below
			> >
			> > CPU utilization for five seconds: 99%/42%;
one minute: 99%; five minutes: 
			> > 99%
			> > PID Runtime(ms) Invoked uSecs 5Sec 1Min 5Min
TTY Process
			> > 1 0 75 0 0.00% 0.00% 0.00% 0 Chunk Manager
			> >
			> >
			> > 5 472509060 101324023 4663 7.65% 8.80% 8.84%
0 Pool Manager
			> >
			> > 37 10810547881019294234 1060 22.79% 25.16%
25.51% 0 IP Input
			> >
			> >
			> > 101 705044020 800103660 881 18.89% 21.35%
19.34% 0 L2TP data
			> > daemon 
			> > 102 53153196 10197928 5212 2.19% 0.46% 0.45%
0 L2TP mgmt
			> > daemon
			> >
			> >
			> > It seemed that Pool Manager + IP Input +
L2TP data daemon together is
			> > causing this issue. I was searching for
documents regarding this on google 
			> > and came to this mailing list. I am
wondering if you guys can help me out by
			> > identifying the mis-configuration that I
have on my end as it is my
			> > understanding that a 7206 should at least
take close 1000 pppoe sessions. 
			> > Thank You in advance for your input.
			> >
			> >
			> > hostname LNS
			> > !
			> > boot system slot1:c7200-is-mz.122-32.bin
			> > boot system slot1:c7200-is-mz.120-3.T3 
			> > aaa new-model
			> > aaa authentication login default local
			> > aaa authentication login no_rad line
			> > aaa authentication ppp default group radius
local
			> > aaa authentication ppp vpdn group radius 
			> > aaa authorization network default group
radius
			> > aaa authorization configuration default
group radius
			> > aaa accounting delay-start
			> > aaa accounting exec default start-stop group
radius 
			> > aaa accounting network default start-stop
group radius
			> > enable secret 5 XXXXXXXXXXXXXXXXXXXXXXXXXXX
			> > !
			> > clock timezone EST -5
			> > clock summer-time EDT recurring 
			> > ip subnet-zero
			> > no ip source-route
			> > ip cef
			> > !
			> > !
			> > ip name-server XXXXXX
			> > ip name-server XXXXXX
			> > ip name-server XXXXXX
			> > ! 
			> > vpdn enable
			> > !
			> > vpdn-group XXXXXXXX
			> > accept-dialin
			> > protocol l2tp
			> > virtual-template 1
			> > terminate-from hostname XXXXXX
			> > local name XXXXXXX 
			> > lcp renegotiation always
			> > !
			> > interface FastEthernet0/0
			> > ip address X.X.X.X 255.255.255.192
			> > no ip mroute-cache
			> > duplex full
			> > !
			> > interface FastEthernet1/0
			> > no ip address
			> > no ip mroute-cache
			> > duplex full
			> > ! 
			> > interface FastEthernet1/0.401
			> > description !!XXXXXXXXXXXXXXXXXXXXXXXX!!
			> > encapsulation dot1Q 401
			> > ip address 10.70.X.X 255.255.255.252
			> > no ip mroute-cache
			> > !
			> > interface FastEthernet2/0
			> > description !!Internet Feed!!
			> > ip address Y.Y.Y.Y 255.255.255.252
			> > no ip mroute-cache
			> > duplex full
			> > !
			> > interface Virtual-Template1
			> > mtu 1492
			> > ip unnumbered FastEthernet2/0
			> > peer default ip address pool internet1
internet2 
			> > ppp authentication pap vpdn
			> > !
			> > ip local pool internet1 A.A.A.A B.B.B.B
			> > ip local pool internet2 C.C.C.C D.D.D.D
			> > ip classless
			> > ip route 0.0.0.0 0.0.0.0 Y.Y.Y.Y
			> > no ip http server
			> > !
			> > ip radius source-interface FastEthernet0/0 
			> > radius-server host X.X.X.X auth-port 1645
acct-port 1646
			> > radius-server host X.X.X.X auth-port 1645
acct-port 1646
			> > radius-server key 7 ZZZZZZZZZZZZZZZ
			> >
			> > Anthony 
			> >
			> > ________________________________
			> > Be one of the first to try Windows Live
Mail.
			> >
_______________________________________________
			> > cisco-bba mailing list
			> > cisco-bba at puck.nether.net
			> >
https://puck.nether.net/mailman/listinfo/cisco-bba
			> >
			> >
			> >
			
			
			
________________________________

			Be one of the first to try Windows Live Mail.
<http://ideas.live.com/programpage.aspx?versionId=5d21c51a-b161-4314-9b0
e-4911fb2b2e6d> 

			_______________________________________________
			cisco-bba mailing list
			cisco-bba at puck.nether.net 
	
https://puck.nether.net/mailman/listinfo/cisco-bba
			
			
			



-------------- next part --------------
An HTML attachment was scrubbed...
URL: https://puck.nether.net/pipermail/cisco-bba/attachments/20070125/6209f1bd/attachment-0001.html 


More information about the cisco-bba mailing list