2811 vs 2911 CPU

Nikos Nicolaides · ‎09-10-2011

Hello,

We are thinking of replacing our router 2811 with a newer model 2911 dude to high CPU utilizaiton. Can anyone please give us a comparison of the CPU of the routers if applicable? I mean if a 2811 with CPU going up to 80% would it be wize to be replaced with a 2911?

Regards,

Nick

TIA, Nicos Nicolaides

Reza Sharifi · ‎09-10-2011

Nick,

Whether you use 2800 series or 2900, 80% utilization is usually high, unless you are connected to the Internet and carry full routing table with limited memory. Do you have large BGP routing table? what does "sh cpu pros" shows?

HTH

Joseph W. Doherty · ‎09-10-2011

Disclaimer

The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.

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In no event shall Author be liable for any damages whatsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.

Posting

2811 is rated by Cisco at 120 Kpps, the 2911 at 352 Kpps. So it's possible, but not guaranteed, that the newer 2911 will decrease your CPU usage by the same ratio, i.e. from 80% to about 27%.

smogra · ‎09-10-2011

80% cpu is always bad whether it is 2811 or 2911. Before moving to 2911, try checking on 2811 what is the reason which is causing the high cpu and if you can lower it down. May be you are deploying complete routing and that the reason cpu is raising.

Sweta

shehinpm1 · ‎09-11-2011

Hi Nick,

could you please post this command out put

show proc cpu | excl 0.00%__0.00%__0.00%

Nikos Nicolaides · ‎09-11-2011

LOGBG#sh proc c h

LOGBG 08:45:55 AM Monday Sep 12 2011 EEST

666666666655555888886666666666666666666655555555555555544444

444441111155555111117777777777999999999955555222228888888888

100

90

80 *****

70 *************************

60 ********************************************* *****

50 ************************************************************

40 ************************************************************

30 ************************************************************

20 ************************************************************

10 ************************************************************

0....5....1....1....2....2....3....3....4....4....5....5....6

0 5 0 5 0 5 0 5 0 5 0

CPU% per second (last 60 seconds)

575666657557855444433532325534232232233356223211321111111111

879570011944552304574293568858454219753553610416482062764519

100

90 *

80 * *

70 * ** * **

60 ******* ** *** ** **

50 ######***#####* * * ** * **

40 #######*######****** ** * **** * * ***

30 #################****** **##** * ***##*#** * **

20 ##############################*###########*##* *** * ** * *

10 ############################################################

0....5....1....1....2....2....3....3....4....4....5....5....6

0 5 0 5 0 5 0 5 0 5 0

CPU% per minute (last 60 minutes)

* = maximum CPU% # = average CPU%

672274435367443763347882222443224343445844447342313665343334888998898997

325622124252824962854758444096785298131064186890564918839241544552769367

100 ** * *

90 ** * ** *****

80 * ** * * ************

70 * * ** ** *** * * * *******#****

60 ** * ** ** *** * * *** ****#**#**#*

50 ** * * *** ** **** * * * *** ** * *** ***##**####*

40 ** *** * **** ** ***** *** * ************* * ****** ***#########*

30 *********************#** ******************** * **********#*##########

20 ******#***#****#****###****************##*#**********###**##############

10 ########################################################################

0....5....1....1....2....2....3....3....4....4....5....5....6....6....7..

0 5 0 5 0 5 0 5 0 5 0 5 0

CPU% per hour (last 72 hours)

* = maximum CPU% # = average CPU%

LOGBG#

LOGBG#show proc cpu | excl 0.00%__0.00%__0.00%

CPU utilization for five seconds: 62%/56%; one minute: 58%; five minutes: 50%

PID Runtime(ms) Invoked uSecs 5Sec 1Min 5Min TTY Process

2 272828 293557 929 0.07% 0.11% 0.08% 0 Load Meter

3 1008 237 4253 0.00% 0.48% 0.12% 514 SSH Process

4 3645068 222629 16372 0.00% 0.17% 0.16% 0 Check heaps

32 38284 1467725 26 0.07% 0.00% 0.00% 0 GraphIt

37 106084 615653 172 0.07% 0.01% 0.00% 0 Net Background

41 3294548 1467831 2244 0.31% 0.30% 0.28% 0 Per-Second Jobs

51 668700 24732 27037 0.00% 0.03% 0.00% 0 Per-minute Jobs

55 30864 440026 70 0.07% 0.00% 0.00% 0 HC Counter Timer

64 164144 5867890 27 0.07% 0.02% 0.00% 0 Netclock Backgro

105 65222224 51633232 1263 3.19% 3.96% 3.48% 0 IP Input

114 123500 1466986 84 0.07% 0.01% 0.00% 0 Spanning Tree

129 146028 2273125 64 0.00% 0.02% 0.00% 0 CEF: IPv4 proces

149 66800 2862115 23 0.07% 0.01% 0.00% 0 Inspect process

152 64936 2862101 22 0.07% 0.00% 0.00% 0 CCE DP URLF cach

160 7925468 352843182 22 1.91% 2.13% 2.10% 0 HQF Shaper Backg

180 19776 9640 2051 0.00% 0.03% 0.00% 0 TPLUS

206 190112 7333659 25 0.00% 0.03% 0.01% 0 Atheros LED Ctro

244 1691236 2888208 585 0.15% 0.18% 0.17% 0 IP NAT Ager

246 149624 2186849 68 0.07% 0.01% 0.00% 0 IP VFR proc

248 996848 1137371 876 0.00% 0.04% 0.04% 0 IP SNMP

249 254144 565129 449 0.00% 0.01% 0.00% 0 PDU DISPATCHER

250 870884 565199 1540 0.00% 0.03% 0.02% 0 SNMP ENGINE

254 2219252 7973160 278 0.15% 0.15% 0.14% 0 NAT MIB Helper

LOGBG#

Here it is. Note that we started work 45 minutes ago.

TIA, Nicos Nicolaides

Leo Laohoo · ‎09-11-2011

What is the IOS version?

What is your WAN speed?

Nikos Nicolaides · ‎09-11-2011

LOGBG#sh ver

Cisco IOS Software, 2800 Software (C2800NM-ADVSECURITYK9-M), Version 12.4(24)T3, RELEASE SOFTWARE (fc2)

Technical Support: http://www.cisco.com/techsupport

Compiled Tue 23-Mar-10 06:43 by prod_rel_team

ROM: System Bootstrap, Version 12.4(1r) [hqluong 1r], RELEASE SOFTWARE (fc1)

LOGBG uptime is 2 weeks, 2 days, 23 hours, 55 minutes

System returned to ROM by power-on

System restarted at 09:01:46 EEST Fri Aug 26 2011

System image file is "flash:c2800nm-advsecurityk9-mz.124-24.T3.bin"

This product contains cryptographic features and is subject to United

States and local country laws governing import, export, transfer and

use. Delivery of Cisco cryptographic products does not imply

third-party authority to import, export, distribute or use encryption.

Importers, exporters, distributors and users are responsible for

compliance with U.S. and local country laws. By using this product you

agree to comply with applicable laws and regulations. If you are unable

to comply with U.S. and local laws, return this product immediately.

A summary of U.S. laws governing Cisco cryptographic products may be found at:

http://www.cisco.com/wwl/export/crypto/tool/stqrg.html

If you require further assistance please contact us by sending email to

export@cisco.com.

Cisco 2811 (revision 53.51) with 247808K/14336K bytes of memory.

Processor board ID FCZ101470JQ

7 FastEthernet interfaces

1 Serial(sync/async) interface

1 Virtual Private Network (VPN) Module

DRAM configuration is 64 bits wide with parity enabled.

239K bytes of non-volatile configuration memory.

62720K bytes of ATA CompactFlash (Read/Write)

Configuration register is 0x2102

LOGBG#

Find attached the sh tech-support file.

Note that there are 2 internet lines: One ADSL of 12 Mb/s down and 1Mb/s up (f0/1) and one metro internet line with 4Mb/s down and 20Mb/s up f(0/0).

TIA, Nicos Nicolaides

Joseph W. Doherty · ‎09-12-2011

Disclaimer

The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.

Liability Disclaimer

In no event shall Author be liable for any damages whatsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.

Posting

From your additional postings, it appears router may be just loaded pushing traffic. If your WAN interfaces tend to load up, i.e. the 12, 4 and 20 Mbps, that would be enough to account for your high CPU load.

Your process CPU loading is a bit higher than it ideally should be, but not enough that it should be a major issue.

I notice this 2811 also has 7 FastEthernet interfaces. Does it do any LAN-to-LAN routing in addition to WAN routing?

If I recall correctly, Cisco recommends at 2811 for only a couple of T1 lines. From my experience, it will top out at 100% at about 20 Mbps duplex.

Nikos Nicolaides · ‎09-12-2011

The switch card is used only for monitor session; no inter VLAN routing is performed. So there is a throughput issue here; Can you verify that a 2911 will be a future-proof solution for our scenario?

TIA, Nicos Nicolaides

Joseph W. Doherty · ‎09-12-2011

Disclaimer

The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.

Liability Disclaimer

In no event shall Author be liable for any damages whatsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.

Posting

Not knowing what you might want to do in the future, cannot guarantee a 2911 will be "future proof". However, Cisco recommends a 2911 for up to 35 Mbps WAN bandwidth and their recommendations tend to be rather conservative. Assuming you don't expect to have more than that, you're likely "future proof".

PS:

Since one of your links is ADSL, wondering if its PPPoE, and if so, if MTU is less than 1500 whether you've configured to allow for that. If not, might account for your IP Input being a higher than necessary.

milan.kulik · ‎09-12-2011

Hi,

the CPU seems to be overloaded due to interrupts.

See

http://www.cisco.com/en/US/products/hw/routers/ps359/products_tech_note09186a00801c2af0.shtml

for issues to check.

HTH,

Milan