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4948 issue.

sajism220
Level 1
Level 1

‎08-01-2011 03:08 AM - edited ‎03-07-2019 01:29 AM

Hi all,

We have a client , which is having 2 4948 switches connected to single 6509 core switch, attached the network reference.

Client is complaing saying that some time CPU spike is happing, I am getting this below process are high in the switch.

SW2#sh processes cpu sorted

CPU utilization for five seconds: 20%/0%; one minute: 16%; five minutes: 15%

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

  47   808993472 360931820       2241 13.75% 10.14%  9.14%   0 Cat4k Mgmt LoPri

  46   234230208 694128276        337  5.35%  5.37%  5.36%   0 Cat4k Mgmt HiPri

  35    45192948  12104135       3733  0.31%  0.31%  0.31%   0 IDB Work        

101     5517220  36812852        149  0.23%  0.23%  0.23%   0 Spanning Tree   

100       23112    131576        175  0.07%  0.00%  0.00%   1 Virtual Exec

The spanning tree is already enabled in this switces.

SW2#sh spanning-tree summary
Switch is in rapid-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 enabled
EtherChannel misconfig guard is enabled
UplinkFast                   is disabled
BackboneFast                 is disabled
Configured Pathcost method used is short

Name                   Blocking Listening Learning Forwarding STP Active
---------------------- -------- --------- -------- ---------- ----------
VLAN0010                     0         0        0          1          1
VLAN0100                     0         0        0          2          2
VLAN0101                     0         0        0          6          6
VLAN0102                     0         0        0          3          3
VLAN0103                     0         0        0         11         11
VLAN0108                     0         0        0          1          1
VLAN0109                     0         0        0          1          1
VLAN0110                     0         0        0          5          5
VLAN0112                     0         0        0          1          1
VLAN0300                     0         0        0          9          9
---------------------- -------- --------- -------- ---------- ----------
10 vlans                     0         0        0         40         40

SW2#sh spanning-tree vlan 101

VLAN0101
  Spanning tree enabled protocol rstp
  Root ID    Priority    0
             Address     0024.f906.3465
             Cost        3
             Port        642 (Port-channel2)
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec

  Bridge ID  Priority    32869  (priority 32768 sys-id-ext 101)
             Address     0025.451c.b040
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec
             Aging Time 300

Interface           Role Sts Cost      Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi1/1               Desg FWD 4         128.1    P2p Edge
Gi1/2               Desg FWD 19        128.2    P2p Edge
Gi1/9               Desg FWD 4         128.9    P2p Edge
Gi1/10              Desg FWD 19        128.10   P2p Edge
Gi1/16              Desg FWD 4         128.16   P2p Edge
Po2                 Root FWD 3         128.642  P2p

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

SW1#sh processes cpu sorted

CPU utilization for five seconds: 29%/0%; one minute: 15%; five minutes: 14%

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

  47  1822037744 849604546       2144 20.79%  8.83%  8.57%   0 Cat4k Mgmt LoPri

  46   4253451441742621573        244  5.11%  4.95%  4.93%   0 Cat4k Mgmt HiPri

   7    59750168   5246116      11389  2.31%  0.31%  0.20%   0 Check heaps     

100        6536      1514       4317  0.31%  0.02%  0.00%   1 Virtual Exec    

  35   111766600  28260288       3954  0.31%  0.31%  0.31%   0 IDB Work        

101    12059940  85360326        141  0.15%  0.19%  0.18%   0 Spanning TreeCPU utilization for five seconds: 29%/0%; one minute: 15%; five minutes: 14%
PID Runtime(ms)   Invoked      uSecs   5Sec   1Min   5Min TTY Process
  47  1822037744 849604546       2144 20.79%  8.83%  8.57%   0 Cat4k Mgmt LoPri
  46   4253451441742621573        244  5.11%  4.95%  4.93%   0 Cat4k Mgmt HiPri
   7    59750168   5246116      11389  2.31%  0.31%  0.20%   0 Check heaps     
100        6536      1514       4317  0.31%  0.02%  0.00%   1 Virtual Exec    
  35   111766600  28260288       3954  0.31%  0.31%  0.31%   0 IDB Work        
101    12059940  85360326        141  0.15%  0.19%  0.18%   0 Spanning Tree

SW1#sh spanning-tree summary
Switch is in rapid-pvst mode
Root bridge for: none
Extended system ID           is enabled
Portfast Default             is disabled
PortFast BPDU Guard Default  is enabled
Portfast BPDU Filter Default is disabled
Loopguard Default            is enabled
EtherChannel misconfig guard is enabled
UplinkFast                   is disabled
BackboneFast                 is disabled
Configured Pathcost method used is short

Name                   Blocking Listening Learning Forwarding STP Active
---------------------- -------- --------- -------- ---------- ----------
VLAN0010                     0         0        0          1          1
VLAN0100                     0         0        0          2          2
VLAN0101                     0         0        0          8          8
VLAN0102                     0         0        0          3          3
VLAN0103                     0         0        0          9          9
VLAN0108                     0         0        0          1          1
VLAN0109                     0         0        0          1          1
VLAN0110                     0         0        0          1          1
VLAN0112                     0         0        0          1          1
VLAN0300                     0         0        0          7          7
---------------------- -------- --------- -------- ---------- ----------
10 vlans                     0         0        0         34         34

SW1#sh spanning-tree vlan 101

VLAN0101
  Spanning tree enabled protocol rstp
  Root ID    Priority    0
             Address     0024.f906.3465
             Cost        3
             Port        643 (Port-channel3)
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec

  Bridge ID  Priority    32869  (priority 32768 sys-id-ext 101)
             Address     0025.451c.b2c0
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec
             Aging Time 300

Interface           Role Sts Cost      Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi1/1               Desg FWD 4         128.1    P2p Edge
Gi1/2               Desg FWD 100       128.2    P2p Edge
Gi1/9               Desg FWD 4         128.9    P2p Edge
Gi1/10              Desg FWD 19        128.10   P2p Edge
Gi1/16              Desg FWD 4         128.16   P2p Edge
Gi1/37              Desg FWD 19        128.37   P2p Edge
Gi1/38              Desg FWD 19        128.38   P2p Edge
Po3                 Root FWD 3         128.643  P2p

also some time I am getting this logs also , switch error c4k_ebm-4-hostflapping host

can some one guide me for this.

Regards

-Saji

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6 Replies 6

smogra
Cisco Employee
Cisco Employee

‎08-01-2011 06:40 AM

Hi, 

Please refer to the below document which explains the cause of seeing above mentioned error message:

http://www.cisco.com/en/US/products/hw/switches/ps4324/products_tech_note09186a008063c36f.shtml#cg1

The symptoms include the high cpu which is exactly what you are seeing in your client's device. You must have spanning tree enable but could be a probability that it breaks for a while and then converges.

So I would recommend that you check the spanning tree settings when you see high cpu because high cpu cases are generally resolved wen they are seen live.

Hope that helps.

Cheers

Sweta

p.s. please rate the answer if the content was useful.

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sajism220
Level 1
Level 1
In response to smogra

‎08-01-2011 07:55 AM

Hi Sweta,

The Spanning tree is already enabled and the root bridge is my core 6509, this 4948 is just a layer 2 device.

Regards

-Saji

0 Helpful

Somasundaram Jayaraman
Cisco Employee
Cisco Employee
In response to sajism220

‎08-05-2011 03:56 PM 

Hi Saji, 

From the show proc cpu sorted output,
 
CPU utilization for five seconds: 20%/0%; one minute: 16%; five minutes: 15%


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


  47   808993472 360931820       2241 13.75% 10.14%  9.14%   0 Cat4k Mgmt LoPri 


  46   234230208 694128276        337  5.35%  5.37%  5.36%   0 Cat4k Mgmt HiPri 

These two processes aggregate multiple platform-specific processes which 
perform the essential management functions on the switch. These 
processes process control plane as well as data packets that need to be 
software-switched or processed.

Could you share the following outputs

show processes cpu  sorted
show platform health
show platform cpu packet statistics all
sh platform cpu packet driver
debug platform packet all receive buffer (Captures all packets sent to CPU in a circular buffer)
show platform CPU packet buffered (Displays all the details of the packets buffered by the previous command)


From the output of show platform cpu packet buffered, we can track the source ip & source mac of 
the packet which is hitting the cpu.

Also i would suggest you to enable mac move notification, so that if there is any mac-flaps happening in the n/w
we will come to know. To enable mac-move notification,

conf ter
mac address-table notification mac-move

Here is the link for troubleshooting high cpu on 4500 switches:



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


Hope this helps.

Cheers 
Somu

Rate this answer if you found the content was useful.

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sajism220
Level 1
Level 1
In response to Somasundaram Jayaraman

‎08-06-2011 08:49 PM

Hello Somasundaram,

Here is the requested logs.

111312-sh platform cpu packet driver-SW2.zip
0 Helpful

sajism220
Level 1
Level 1
In response to Somasundaram Jayaraman

‎08-06-2011 08:51 PM

Some more logs

111314-SW2-4948-HELTH.zip
0 Helpful

Somasundaram Jayaraman
Cisco Employee
Cisco Employee
In response to sajism220

‎08-07-2011 11:36 AM

Hi,

From show platform cpu packet statistics,

Packets Dropped In Processing by CPU event

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

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

Control Packet                       0         0         0         0          0

Input Acl                        47945         0         0         0          0

from show platform health,

K2AclCamMan kx stats   1.00   2.47     10      5  100  500    0   0    0  1404:33

Looking at the 'show process cpu' the one with the highest process are Cat4k

Mgmt LoPri,and Cat4k Mgmt Hi Pri.

'Cat4k Mgmt LoPri' schedules all cat4k platform-dependent processes, which

exceed the CPU target utilization.

You can see target and actual CPU utilization in the output of 'show platform health'

'Cat4k Mgmt HiPri' manages processes which are staying under CPU target

utilization. Misbehaving processes are handled by 'Cat4k Mgmt LoPri'.

NOTE: The common misconception is that high CPU utilization indicates the

depletion of resources on a device and the threat of a crash. A capacity issue is one of

the symptoms of high CPU utilization on Cisco IOS routers. However, a capacity issue is

almost never a symptom of high CPU utilization with hardware-based forwarding switches like

the Catalyst 4500. The Catalyst 4500 is designed to forward packets in the hardware

application-specific integrated circuit (ASIC) and reach traffic-forwarding

speeds of up to 102 million packets per second (Mpps).

The only thing I can see from the

#show platform health

K2AclCamMan kx stats   1.00   2.47     10      5  100  500    0   0    0  1404:33

Please capture "show platform health" several times when the CPU is high in

order to further identify the platform-specific processes.

For your reference, please go to this link for troubleshooting High CPU on

cat4500 platforms.

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

Hope this helps

Cheers

Somu

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