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Very High CPU utilization core switch 4503

Sihanu N
Level 1
Level 1

Hi Experts,

We  had a core switch(30 vlans) in our environment and it's noticed that  CPU utilization of the core switch is showing high during recent days. I  have checked logs and processes, but couldn't find the root cause. The  issue found only in the office hourly only(after that the cpu  utilization is idle and normal). I have already referred the following  link to troubleshoot the issue "

http://www.cisco.com/en/US/products/hw/switches/ps663/products_tech_note09186a00804cef15.shtml

"

Please see the following outputs from the core switch

CPU utilization for five seconds: 99%/0%; one minute: 99%; five minutes: 99%

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

  30   6687557041432420936        466 47.52% 47.10% 45.98%   0 Cat4k Mgmt LoPri

  55  30667074884269560256          0 45.36% 45.50% 45.85%   0 IP Input

  29  28552856922870089254          0  3.59%  3.50%  3.57%   0 Cat4k Mgmt HiPri

  49   405212948 846027881        478  1.03%  0.99%  0.99%   0 Spanning Tree

  59    56846588 590581776         96  0.71%  0.87%  0.88%   0 HSRP (Standby)

   3    18379520 156281914        117  0.23%  0.23%  0.23%   0 OSPF Hello

117         116       146        794  0.15%  0.08%  0.02%   2 Virtual Exec

  18    42606344 200951937        212  0.07%  0.07%  0.07%   0 ARP Input

Core1#sh platform health

                     %CPU   %CPU    RunTimeMax   Priority  Average %CPU  Total

                     Target Actual Target Actual   Fg   Bg 5Sec Min Hour  CPU

Lj-poll                1.00   0.02      2      0  100  500    0   0    0  145:58

GalChassisVp-review    3.00   0.15     10     14  100  500    0   0    0  732:59

S2w-JobEventSchedule  10.00   0.44     10      9  100  500    0   0    0  2694:0

0

Stub-JobEventSchedul  10.00   0.00     10      0  100  500    0   0    0  0:00

StatValueMan Update    1.00   0.08      1      1  100  500    0   0    0  364:31

Pim-review             0.10   0.00      1      1  100  500    0   0    0  34:51

Ebm-host-review        1.00   0.00      8      4  100  500    0   0    0  91:39

Ebm-port-review        0.10   0.00      1      0  100  500    0   0    0  3:02

Protocol-aging-revie   0.20   0.00      2      0  100  500    0   0    0  0:09

Acl-Flattener          1.00   0.00     10      5  100  500    0   0    0  0:00

KxAclPathMan create/   1.00   0.00     10      5  100  500    0   0    0  0:03

KxAclPathMan update    2.00   0.00     10      0  100  500    0   0    0  30:18

KxAclPathMan reprogr   1.00   0.00      2      0  100  500    0   0    0  25:00

TagMan-RecreateMtegR   1.00   0.00     10      0  100  500    0   0    0  0:00

K2CpuMan Review       30.00  41.56     30     33  100  500   39  44   32  96152:

23

K2AccelPacketMan: Tx  10.00   2.31     20      1  100  500    2   2    5  22504:

47

K2AccelPacketMan: Au   0.10   0.00      0      0  100  500    0   0    0  0:00

K2AclMan-taggedFlatA   1.00   0.00     10      0  100  500    0   0    0  0:00

K2AclCamMan stale en   1.00   0.00     10      0  100  500    0   0    0  0:00

K2AclCamMan hw stats   3.00   0.19     10      5  100  500    0   0    0  2336:3

7

K2AclCamMan kx stats   1.00   0.66     10      5  100  500    0   0    0  966:25

K2AclCamMan Audit re   1.00   0.00     10      5  100  500    2   0    0  1112:3

8

K2AclPolicerTableMan   1.00   0.00     10      2  100  500    0   0    0  88:31

K2L2 Address Table R   2.00   0.29     12      5  100  500    0   0    0  827:26

K2L2 New Static Addr   2.00   0.00     10      5  100  500    0   0    0  0:02

K2L2 New Multicast A   2.00   0.00     10      5  100  500    0   0    0  0:01

K2L2 Dynamic Address   2.00   0.00     10      5  100  500    0   0    0  0:00

K2L2 Vlan Table Revi   2.00   0.00     12      8  100  500    0   0    0  0:03

K2 L2 Destination Ca   2.00   0.00     10      0  100  500    0   0    0  0:00

K2PortMan Review       2.00   1.61     15     11  100  500    1   1    1  8004:4

0


----------------------------------------------------------------------------------------------------------------------------------------

Core1#sh platform cpu packet statistics

Packets Dropped In Hardware By CPU Subport (txQueueNotAvail)

CPU Subport  TxQueue 0       TxQueue 1       TxQueue 2       TxQueue 3

------------ --------------- --------------- --------------- ---------------

           0               0               0               0       421934692

           2               0          101147               0               0

RkiosSysPacketMan:

Packet allocation falures: 0

Packet Buffer(Software Common) allocation falures: 0

Packet Buffer(Software ESMP) allocation falures: 0

Packet Buffer(Software EOBC) allocation falures: 0

IOS Packet Buffer Wrapper allocation falures: 0

Packets Dropped In Processing Overall

Total                5 sec avg 1 min avg 5 min avg 1 hour avg

-------------------- --------- --------- --------- ----------

                  72         0         0         0          0

Packets Dropped In Processing by CPU event

Event             Total                5 sec avg 1 min avg 5 min avg 1 hour avg

----------------- -------------------- --------- --------- --------- ----------

SA Miss                             16         0         0         0          0

Packets Dropped In Processing by Priority

Priority          Total                5 sec avg 1 min avg 5 min avg 1 hour avg

----------------- -------------------- --------- --------- --------- ----------

Normal                              56         0         0         0          0

Medium                              72         0         0         0          0

Packets Dropped In Processing by Reason

Reason             Total                5 sec avg 1 min avg 5 min avg 1 hour avg

------------------ -------------------- --------- --------- --------- ----------

SrcAddrTableFilt                     16         0         0         0          0

L2DstDrop                             2         0         0         0          0

NoDstPorts                            4         0         0         0          0

NoFloodPorts                         50         0         0         0          0

Total packet queues 16

Packets Received by Packet Queue

Queue                  Total           5 sec avg 1 min avg 5 min avg 1 hour avg

---------------------- --------------- --------- --------- --------- ----------

Control                     1592264321        61        52        45         34

Host Learning                  1140162         0         0         0          0

L3 Fwd High                        149         0         0         0          0

L3 Fwd Medium                        3         0         0         0          0

L3 Fwd Low                 18667481859      1558      1390      1177        943

L2 Fwd Medium                      255         0         0         0          0

L2 Fwd Low                   425118994        19         9         9          4

L3 Rx High                         499         0         0         0          0

L3 Rx Low                     54609808         0         0         0          0

RPF Failure                        134         0         0         0          0

ACL fwd(snooping)            426175149        16        10         7          0

Packets Dropped by Packet Queue

Queue                  Total           5 sec avg 1 min avg 5 min avg 1 hour avg

---------------------- --------------- --------- --------- --------- ----------

Host Learning                   299235         0         0         0          0

L3 Fwd Low                        1732         0         0         0          0

L2 Fwd Low                       63674         0         0         0          0

----------------------------------------------------------------------------------------------------------------------------------------

Core1# sh spanning-tree summary

Switch is in pvst mode

Root bridge for: none

Extended system ID           is enabled

Portfast Default             is disabled

PortFast BPDU Guard Default  is disabled

Portfast BPDU Filter Default is disabled

Loopguard Default            is disabled

EtherChannel misconfig guard is enabled

UplinkFast                   is disabled

BackboneFast                 is disabled

Configured Pathcost method used is short

Name                   Blocking Listening Learning Forwarding STP Active

---------------------- -------- --------- -------- ---------- ----------

VLAN0001                     2         0        0          5          7

VLAN0044                     2         0        0          5          7

VLAN0055                     2         0        0          5          7

VLAN0066                     2         0        0          5          7

VLAN0100                     2         0        0          5          7

VLAN0110                     2         0        0          5          7

VLAN0111                     2         0        0          5          7

VLAN0112                     2         0        0          5          7

VLAN0113                     2         0        0          5          7

VLAN0114                     2         0        0          5          7

VLAN0115                     2         0        0          5          7

VLAN0116                     2         0        0          5          7

VLAN0117                     2         0        0          5          7

VLAN0118                     2         0        0          5          7

VLAN0119                     2         0        0          5          7

VLAN0120                     2         0        0          5          7

VLAN0121                     2         0        0          5          7

VLAN0122                     2         0        0          5          7

VLAN0123                     2         0        0          5          7

VLAN0124                     2         0        0          5          7

Name                   Blocking Listening Learning Forwarding STP Active

---------------------- -------- --------- -------- ---------- ----------

VLAN0125                     2         0        0          5          7

VLAN0126                     2         0        0          5          7

VLAN0127                     2         0        0          5          7

VLAN0128                     2         0        0          5          7

VLAN0129                     2         0        0          5          7

VLAN0130                     2         0        0          5          7

VLAN0131                     2         0        0          5          7

VLAN0132                     2         0        0          5          7

VLAN0200                     2         0        0          5          7

VLAN0555                     2         0        0          5          7

---------------------- -------- --------- -------- ---------- ----------

30 vlans                    60         0        0        150        210

----------------------------------------------------------------------------------------------------------------------------------------

Core1#sh logging

Syslog logging: enabled (0 messages dropped, 30 messages rate-limited, 0 flushes

, 0 overruns, xml disabled, filtering disabled)

    Console logging: level debugging, 450 messages logged, xml disabled,

                     filtering disabled

    Monitor logging: level informational, 0 messages logged, xml disabled,

                     filtering disabled

    Buffer logging: level debugging, 479 messages logged, xml disabled,

                    filtering disabled

    Exception Logging: size (8192 bytes)

    Count and timestamp logging messages: disabled

    Trap logging: level notifications, 376 message lines logged

        Logging to 10.55.44.11, 16 message lines logged, xml disabled,

               filtering disabled

Log Buffer (4096 bytes):

1y4w: %C4K_L2MAN-6-INVALIDSOURCEADDRESSPACKET: (Suppressed 2 times)Packet receiv

ed with invalid source MAC address (00:00:00:00:00:00) on port Gi3/2 in vlan 1

1y4w: %C4K_L2MAN-6-INVALIDSOURCEADDRESSPACKET: Packet received with invalid sour

ce MAC address (00:00:00:00:00:00) on port Gi3/2 in vlan 1

1y4w: %C4K_L2MAN-6-INVALIDSOURCEADDRESSPACKET: (Suppressed 1 times)Packet receiv

ed with invalid source MAC address (00:00:00:00:00:00) on port Gi3/2 in vlan 1

Note: Each Invalid source mac entry in each day from same port (above is the output after clearing logs before 3 days)

My queries regarding the issues are following

1) How can we find root cause regarding the high cpu utilization?

2) Is a single invalid mac address makes the cpu highly utilized for suppressing it?

Please provide your valuable suggestions regarding this issue

Advanced Thanks & Regards,

Sihanu

11 Replies 11

fsebera
Level 4
Level 4

I have noticed many packets traveling around my network with invalid source MAC addresses - turns out these packets were from two different sources.

One source was valid, clients requesting DHCP addresses

The second was from a wanna-be technical security engineer trying out new software - just to see what would happen.

The second was invalid and removing him from the production network solved that issue.

:

I have also seen time of high utilization, especially on less-smart 4500 platforms, spanning-tree loops. The 4500 could not keep up with the traffic and thus ran the CPU 99%. And this was fixed by mapping out the net and breaking the loop.

:

Just last week, I had to change the IOS level running as something within the IOS caused 99% utilization 100% of the time.

:

Don't know if any of this helps, hopefully so

Regards

Frank

Hi Frank,

Many thanks for your information update,

Please let us know following details

1) How to find and break loops in the core switch 4503?

2) Please let me know the stable ios version for 4503?

Thanks & Regards,

Sihanu N

Hi Sihanu,

Before we start down the spanning-tree road, I think it might be more beneficial to figure out what is causing the high cpu utilization and then focus on that issue. Shown below is a link to a Cisco doc the help identify reasons for high cpu issues on 4500 series switches. Let us know how it goes

Identify the Reason for High CPU Utilization on Catalyst 4500

http://www.cisco.com/en/US/products/hw/switches/ps663/products_tech_note09186a00804cef15.shtml

Hi Frank,

I have already referred the cisco document mentioned, but couldn't find the root cause regarding this issue. Please see my first post in this discussion. All the required show command outputs are posted in that, it would be great if you could find and provide the exact root cause from those outputs and let me know any more show command output needs to be posted for the kind reference.

Its noted that one of the access switch in our environment is the root bridge, any issue related to this with the high cpu utilization of the core switch?

Kindly furnish the solution for this issue

Thanks and Regards,

Sihanu N

Hi Sihanu

Looking through the output in your original post, some of the outputs are missing. The output you listed is VERY hard to follow due to your text font choice.

When you paste output from the CLI into this post, select font COURIER NEW which makes all the data fields line up, selecting size 8 usually allows each line to not wrap to the next line (not always, but usually).

From the url provided in my previous post, the troubleshooting doc indicates if you receive K2CpuMan (which you did) but you failed to provide the next steps or output.

:

Perhaps the document will not help, maybe it will.

One other thought, if spanning-tree is the problem you will see spanning-tree recalculating numbers very high. If the recalculating numbers are low, move onto something else.

:

Don't have any solid details at this point, try to follow the steps in the troubleshooing doc and lets see what shows up.

Another idea is to open a TAC case as the Cisco techs will focus on your issue - with you.

Best Regards

Frank

:

The general troubleshooting steps are:

     Issue the show processes cpu command in order to identify the Cisco IOS processes that consume CPU cycles.

     Issue the show platform health command in order to further identify the platform-specific processes.

     If the highly active process is K2CpuMan Review , issue the show platform cpu packet statistics command in order to identity the type of traffic that hits the CPU.

     If the activity is not due to the K2CpuMan Review process, skip Step 4 and go on to Step 5.

     Identify the packets that hit the CPU with use of the Troubleshooting Tools to Analyze the Traffic Destined to the CPU, if necessary.

     An example of the troubleshooting tools to use is the CPU Switched Port Analyzer (SPAN).

    Review this document and the section Troubleshoot Common High CPU Utilization Problems for common causes.

    If you still cannot identify the root cause, contact Cisco Technical Support.

Hi Frank,

Many many thanks for your valuable suggessions and solution steps. Please see the output in correct format of show cpu packet statistics

Core1#  sh platform cpu packet statistics

Packets Dropped In Hardware By CPU Subport (txQueueNotAvail)

CPU Subport     TxQueue 0       TxQueue 1       TxQueue 2       TxQueue 3

------------ --------------- --------------- --------------- ---------------

       0           0             0               0           421854793

       2           0            101147            0               0

RkiosSysPacketMan:

Packet allocation falures: 0

Packet Buffer(Software Common) allocation falures: 0

Packet Buffer(Software ESMP) allocation falures: 0

Packet Buffer(Software EOBC) allocation falures: 0

IOS Packet Buffer Wrapper allocation falures: 0

Packets Dropped In Processing Overall

Total                5 sec avg 1 min avg 5 min avg 1 hour avg

-------------------- --------- --------- --------- ----------

                  72         0         0         0          0

Packets Dropped In Processing by CPU event

Event             Total                5 sec avg 1 min avg 5 min avg 1 hour avg

----------------- -------------------- --------- --------- --------- ----------

SA Miss                             16         0         0         0          0

Packets Dropped In Processing by Priority

Priority          Total                5 sec avg 1 min avg 5 min avg 1 hour avg

----------------- -------------------- --------- --------- --------- ----------

Normal                              56         0         0         0          0

Medium                              72         0         0         0          0

Packets Dropped In Processing by Reason

Reason             Total                5 sec avg 1 min avg 5 min avg 1 hour avg

------------------ -------------------- --------- --------- --------- ----------

SrcAddrTableFilt                     16         0         0         0          0

L2DstDrop                             2         0         0         0          0

NoDstPorts                            4         0         0         0          0

NoFloodPorts                         50         0         0         0          0

Total packet queues 16

Packets Received by Packet Queue

Queue                  Total           5 sec avg 1 min avg 5 min avg 1 hour avg

---------------------- --------------- --------- --------- --------- ----------

Control                     1591972297        61        52        45         34

Host Learning                  1139997         0         0         0          0

L3 Fwd High                        149         0         0         0          0

L3 Fwd Medium                        3         0         0         0          0

L3 Fwd Low                 18661965352       823       796       769        880

L2 Fwd Medium                      255         0         0         0          0

L2 Fwd Low                   425038440        24        10         8          4

L3 Rx High                         499         0         0         0          0

L3 Rx Low                     54595043         3         1         0          0

RPF Failure                        134         0         0         0          0

ACL fwd(snooping)            426097006        15        10         7          0

Packets Dropped by Packet Queue

Queue                  Total           5 sec avg 1 min avg 5 min avg 1 hour avg

---------------------- --------------- --------- --------- --------- ----------

Host Learning                   299235         0         0         0          0

L3 Fwd Low                        1732         0         0         0          0

L2 Fwd Low                       63674        0         0         0          0


show logging output

1y4w: %C4K_L2MAN-6-INVALIDSOURCEADDRESSPACKET: (Suppressed 2 times)Packet receiv

ed with invalid source MAC address (00:00:00:00:00:00) on port Gi3/2 in vlan 1

1y4w: %C4K_L2MAN-6-INVALIDSOURCEADDRESSPACKET: Packet received with invalid sour

ce MAC address (00:00:00:00:00:00) on port Gi3/2 in vlan 1

1y4w: %C4K_L2MAN-6-INVALIDSOURCEADDRESSPACKET: (Suppressed 1 times)Packet receiv

ed with invalid source MAC address (00:00:00:00:00:00) on port Gi3/2 in vlan 1

1y5w: %C4K_L2MAN-6-INVALIDSOURCEADDRESSPACKET: (Suppressed 1 times)Packet receiv

ed with invalid source MAC address (00:00:00:00:00:00) on port Gi3/2 in vlan 1

1y5w: %C4K_L2MAN-6-INVALIDSOURCEADDRESSPACKET: Packet received with invalid sour

ce MAC address (00:00:00:00:00:00) on port Gi3/2 in vlan 1

We are getting an Invalid mac address by analysing the logs everyday. We decided to span the traffic for monitoring for Gi3/2, and wireshark to monitor the traffic.

Kindly let me know the suggessions to the following queries

1) Is any other tool rather than Wireshark to monitor the traffic effectively find the source of invalid mac address?

2) Is any other debugging in core swich can find the exact reason for the high cpu utilization?

3) Please clarify the monitoring of traffic to the CPU using span(which all are the physical interfaces or vlan interface to monitor using span))?

Thanks and Regards,

Sihanu N

Core1#  sh platform cpu packet statistics

Packets Dropped In Hardware By CPU Subport (txQueueNotAvail)

CPU Subport  TxQueue 0       TxQueue 1       TxQueue 2       TxQueue 3

------------ --------------- --------------- --------------- ---------------

           0               0               0               0       421854793

           2               0          101147               0               0

RkiosSysPacketMan:

Packet allocation falures: 0

Packet Buffer(Software Common) allocation falures: 0

Packet Buffer(Software ESMP) allocation falures: 0

Packet Buffer(Software EOBC) allocation falures: 0

IOS Packet Buffer Wrapper allocation falures: 0

Packets Dropped In Processing Overall

Total                5 sec avg 1 min avg 5 min avg 1 hour avg

-------------------- --------- --------- --------- ----------

                  72         0         0         0          0

Packets Dropped In Processing by CPU event

Event             Total                5 sec avg 1 min avg 5 min avg 1 hour avg

----------------- -------------------- --------- --------- --------- ----------

SA Miss                             16         0         0         0          0

Packets Dropped In Processing by Priority

Priority          Total                5 sec avg 1 min avg 5 min avg 1 hour avg

----------------- -------------------- --------- --------- --------- ----------

Normal                              56         0         0         0          0

Medium                              72         0         0         0          0

Packets Dropped In Processing by Reason

Reason             Total                5 sec avg 1 min avg 5 min avg 1 hour avg

------------------ -------------------- --------- --------- --------- ----------

SrcAddrTableFilt                     16         0         0         0          0

L2DstDrop                             2         0         0         0          0

NoDstPorts                            4         0         0         0          0

NoFloodPorts                         50         0         0         0          0

Total packet queues 16

Packets Received by Packet Queue

Queue                  Total           5 sec avg 1 min avg 5 min avg 1 hour avg

---------------------- --------------- --------- --------- --------- ----------

Control                     1591972297        61        52        45         34

Host Learning                  1139997         0         0         0          0

L3 Fwd High                        149         0         0         0          0

L3 Fwd Medium                        3         0         0         0          0

L3 Fwd Low                 18661965352       823       796       769        880

L2 Fwd Medium                      255         0         0         0          0

L2 Fwd Low                   425038440        24        10         8          4

L3 Rx High                         499         0         0         0          0

L3 Rx Low                     54595043         3         1         0          0

RPF Failure                        134         0         0         0          0

ACL fwd(snooping)            426097006        15        10         7          0

Packets Dropped by Packet Queue

Queue                  Total           5 sec avg 1 min avg 5 min avg 1 hour avg

---------------------- --------------- --------- --------- --------- ----------

Host Learning                   299235         0         0         0          0

L3 Fwd Low                        1732         0         0         0          0

L2 Fwd Low                       63674        0         0         0          0

Sihanu,

1. Yes Wireshark is the best tool to identify issues on the network but let me also say, this tool is not for the new engineer as there is toooooooooo much data to understand.

:

2. There are other tools but the output is very similar to the output in Wireshark - pages and pages and pages, again not for a new engineer as there is tooooooooooooooooooooooooooo much data and the IOS tools can render your device unmanageable. Monitoring with Wireshark is the best and saftest way to proceed.

:

3. To narrow your search, start monitoring the vlan and or trunk link(s), then when you see specific traffic, note the details and this will allow you to focus on the exact port and/or physical interface(s).

:

4. Not sure if the logging output provided [in your last post] is complete - if you are only seeing a few log entries with invalid MAC entries, to me this is a mute and minor issue since the box is processing Gigbytes of traffic.

:

:

A couple of things I would do before moving forward:

1. set the date and time

2. set logging levels [to buffer] to see debugging-level messages

3. Consider (ONLY by managements approval) reloading your switch as it has been in operation for more than a year. Reloading may remove some unknown (stuck) session(s) - no guarantee but may help.

4. If you reload, reset the date and time (as it dosn't appear you are using NTP.)

5. If problem remains - Open a TAC case to get dedicate support.

:

HTH

Frank

Hi Frank,

Thanks for all your support and sorry for the delayed reply.

Any way we are planning to implement span traffic and monitor the traffic to find root cause. But we have already configured the time manually and its showing correct when we check the clock of the swich.

1) Why time is not showing in the logs entry (now its like 1y 5w or 1y 6w)?

2)Also syslog server is also implemented recently but for the switches its not receivng configured trap levels to the syslog server(only console messages are getting), for routers and asa's its getting according to the trap levels we set, What might be the reason for this issue?

Thanks and Regards,

Sihanu N

This will add timestamps to your log messages

service timestamps log datetime

service timestamps debug datetime

Send logging messages to a remote syslog server

logging

HTH

Frank

Hi Frank,

Sorry for the delayed reply for the post

Thanks for your valuable reply to my queries. It works like a charm.

Thanks and Regards

Sihanu N

Just want to share i resolved my issue by disabling ip redirects in my interface Vlans. there was one Vlan that was causing the issue, and CPU dropped from 80% to 30%. Happy days.

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