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High CPU usage for Catalyst 3750X on IP Input proccess

Dago_O
Level 1
Level 1

Dear Community members,

 

I need your advise for troubleshooting a high CPU usage problem on a Catalyst 3750X L3 switch, which is the core one in my network.  This problem is producing high latency and data lost that is driving my network slow and unstable.

So, the evidence.  This is the output of "show proc cpu sorted" command

 

#show proc cpu sorted
CPU utilization for five seconds: 98%/28%; one minute: 99%; five minutes: 99%
 PID Runtime(ms)     Invoked      uSecs   5Sec   1Min   5Min TTY Process
 214    41003600    13944778       2940 24.15% 25.21% 25.35%   0 IP Input         
 169    34067372     3928624       8671 16.31% 14.55% 14.37%   0 Hulc LED Process
 232    20500311     2892288       7087  8.95%  8.43%  8.43%   0 Spanning Tree    
 125    19816534     4237944       4675  5.59%  7.24%  7.74%   0 hpm main process
  12     3744640     2199415       1702  2.87%  2.56%  2.45%   0 ARP Input        
  85     1858596      630601       2947  1.27%  0.95%  0.89%   0 RedEarth Tx Mana
 129     2207888      176060      12540  0.95%  1.04%  1.03%   0 hpm counter proc
 212     2836209      795249       3566  0.79%  1.46%  1.32%   0 IP ARP Adjacency
  53      137483        4075      33738  0.79%  0.09%  0.06%   0 Per-minute Jobs  
 245      608854      166106       3665  0.79%  0.64%  0.54%   0 PI MATM Aging Pr
 121       68235       11682       5841  0.63%  0.07%  0.01%   0 Strider Tcam Mem
  91     1099121       68040      16154  0.47%  0.52%  0.48%   0 Adjust Regions   
 340      471153      649411        725  0.31%  0.27%  0.23%   0 VLAN Manager     
  84      686262      849745        807  0.31%  0.34%  0.36%   0 RedEarth I2C dri
  51      278373     3518118         79  0.31%  0.30%  0.28%   0 Net Input        
 170      398886      133716       2983  0.15%  0.14%  0.15%   0 HL3U bkgrd proce

As you can see, the CPU is completely utilized and the top process is IP Input.  Googleing I learned that the idea is to use interrupt-level switching (Fast,CEF, between others) instead of proccess-level one, so there is no CPU payload on switching.  Checking this...


#show cef interface brief
Interface                       IP-Address      Status  Switching               
Vlan1                           10.100.10.1     up      no dCEF                 
FastEthernet0                   unassigned      down    no dCEF                 
GigabitEthernet1/0/1            unassigned      up      CEF                     
GigabitEthernet1/0/2            unassigned      down    CEF                     
GigabitEthernet1/0/3            unassigned      up      CEF                     
GigabitEthernet1/0/4            unassigned      up      CEF                     
GigabitEthernet1/0/5            unassigned      up      CEF                     
GigabitEthernet1/0/6            unassigned      up      CEF                     
GigabitEthernet1/0/7            unassigned      up      CEF                     
GigabitEthernet1/0/8            unassigned      down    CEF                     
GigabitEthernet1/0/9            unassigned      up      CEF                     
GigabitEthernet1/0/10           unassigned      down    CEF                     
GigabitEthernet1/0/11           unassigned      up      CEF                     
GigabitEthernet1/0/12           unassigned      up      CEF                     
GigabitEthernet1/0/13           unassigned      up      CEF                     
GigabitEthernet1/0/14           unassigned      up      CEF                     
GigabitEthernet1/0/15           unassigned      up      CEF                     
GigabitEthernet1/0/16           unassigned      up      CEF                     
GigabitEthernet1/0/17           unassigned      up      CEF                     
GigabitEthernet1/0/18           unassigned      up      CEF                     
GigabitEthernet1/0/19           unassigned      up      CEF                     
GigabitEthernet1/0/20           unassigned      up      CEF                     
GigabitEthernet1/0/21           unassigned      up      CEF                     
GigabitEthernet1/0/22           unassigned      up      CEF                     
GigabitEthernet1/0/23           unassigned      up      CEF                     
GigabitEthernet1/0/24           unassigned      up      CEF                     
GigabitEthernet1/1/1            unassigned      down    CEF                     
GigabitEthernet1/1/2            unassigned      down    CEF                     
GigabitEthernet1/1/3            unassigned      down    CEF                     
GigabitEthernet1/1/4            unassigned      down    CEF                     
TenGigabitEthernet1/1/1         unassigned      down    CEF                     
TenGigabitEthernet1/1/2         unassigned      down    CEF                     
Null0                           unassigned      up      no CEF                  
Vlan2                           X.X.171.126  up      CEF                     
Vlan3                           unassigned      up      CEF                     
Vlan4                           unassigned      up      CEF                     
Vlan6                           X.X.165.65   up      CEF                     
Vlan7                           X.X.166.190  up      CEF                     
Vlan8                           X.X.152.2    up      CEF                     
Vlan9                           X.X.166.62   up      CEF                     
Vlan10                          unassigned      up      CEF                     
Vlan12                          X.X.161.126  up      CEF                     
Vlan13                          X.X.171.254  up      CEF                     
Vlan14                          X.X.167.254  up      CEF                     
Vlan15                          X.X.166.65   up      CEF                     
Vlan16                          unassigned      up      CEF                     
Vlan17                          X.X.167.62   up      CEF                     
Vlan19                          X.X.161.190  up      CEF                     
Vlan21                          X.X.167.126  up      CEF                     
Vlan22                          X.X.171.158  up      CEF                     
Vlan27                          X.X.162.226  up      CEF                     
Vlan28                          X.X.162.242  up      CEF                     
Vlan30                          10.201.6.67     up      CEF                     
Vlan60                          192.168.60.1    up      CEF                     
Vlan61                          unassigned      up      CEF                     
Vlan100                         192.168.100.1   up      CEF                     
Vlan200                         unassigned      up      CEF                     
Vlan201                         unassigned      up      CEF                     
Vlan240                         X.X.168.253  up      no dCEF                 
Vlan250                         X.X.171.190  up      CEF                     
Vlan251                         192.168.101.1   up      CEF                     
Vlan252                         192.168.102.1   up      CEF                     
Vlan253                         192.168.103.30  up      CEF                     
Vlan260                         X.X.162.190  up      CEF                     
Vlan280                         unassigned      up      CEF                     
Vlan281                         unassigned      down    CEF                     
Vlan298                         unassigned      down    CEF                     
Vlan301                         unassigned      down    CEF                     
StackPort1                      unassigned      down    CEF                     
Virtual1                        unassigned      up      -                       
Virtual2                        unassigned      up      -    

I can see that CEF is enabled on almost every interface, but checking "show interface switching" (output cropped for readability)

#show interface switching  
Vlan1
          Throttle count          0
                   Drops         RP       1139         SP          0
             SPD Flushes       Fast          0        SSE          0
             SPD Aggress       Fast          0
            SPD Priority     Inputs          0      Drops          0

    Protocol  IP                  
          Switching path    Pkts In   Chars In   Pkts Out  Chars Out
                 Process     339540   75121303      57097    4611829
            Cache misses          0          -          -          -
                    Fast          0          0         11       1053
               Auton/SSE          0          0          0          0

    Protocol  ARP                 
          Switching path    Pkts In   Chars In   Pkts Out  Chars Out
                 Process    1596666   95800784      72413    4344780
            Cache misses          0          -          -          -
                    Fast          0          0          0          0
               Auton/SSE          0          0          0          0

    NOTE: all counts are cumulative and reset only after a reload.
Vlan2

    Protocol  IP                  
          Switching path    Pkts In   Chars In   Pkts Out  Chars Out
                 Process    2816137  201283125      10400    1470747
            Cache misses          0          -          -          -
                    Fast       1205     183277         10       2542
               Auton/SSE          0          0          0          0

    Protocol  ARP                 
          Switching path    Pkts In   Chars In   Pkts Out  Chars Out
                 Process     132743    7964580      86383    5182980
            Cache misses          0          -          -          -
                    Fast          0          0          0          0
               Auton/SSE          0          0          0          0

    NOTE: all counts are cumulative and reset only after a reload.
Vlan3

    Protocol  ARP                 
          Switching path    Pkts In   Chars In   Pkts Out  Chars Out
                 Process      68260    4095600          0          0
            Cache misses          0          -          -          -
                    Fast          0          0          0          0
               Auton/SSE          0          0          0          0

    Protocol  Other               
          Switching path    Pkts In   Chars In   Pkts Out  Chars Out
                 Process          2        120          0          0
            Cache misses          0          -          -          -
                    Fast          0          0          0          0
               Auton/SSE          0          0          0          0

    NOTE: all counts are cumulative and reset only after a reload.
Vlan4

    All statistics for this interface are zero.
Vlan6
          Throttle count          0
                   Drops         RP          9         SP          0
             SPD Flushes       Fast          0        SSE          0
             SPD Aggress       Fast          0
            SPD Priority     Inputs          0      Drops          0

    Protocol  IP                  
          Switching path    Pkts In   Chars In   Pkts Out  Chars Out
                 Process    5140914  356471282      23015    2993665
            Cache misses          0          -          -          -
                    Fast        428      39212          6       1135
               Auton/SSE          0          0          0          0

    Protocol  ARP                 
          Switching path    Pkts In   Chars In   Pkts Out  Chars Out
                 Process      13803     828180      16550     993000
            Cache misses          0          -          -          -
                    Fast          0          0          0          0
               Auton/SSE          0          0          0          0

    NOTE: all counts are cumulative and reset only after a reload.
Vlan7

    Protocol  IP                  
          Switching path    Pkts In   Chars In   Pkts Out  Chars Out
                 Process     151934   14734706       7539    1527065
            Cache misses          0          -          -          -
                    Fast        156      14866          6       1315
               Auton/SSE          0          0          0          0

    Protocol  ARP                 
          Switching path    Pkts In   Chars In   Pkts Out  Chars Out
                 Process      10696     641760       9251     555060
            Cache misses          0          -          -          -
                    Fast          0          0          0          0
               Auton/SSE          0          0          0          0

    NOTE: all counts are cumulative and reset only after a reload.
Vlan8
          Throttle count          0
                   Drops         RP      53150         SP          0
             SPD Flushes       Fast          0        SSE          0
             SPD Aggress       Fast          0
            SPD Priority     Inputs          0      Drops          0

    Protocol  IP                  
          Switching path    Pkts In   Chars In   Pkts Out  Chars Out
                 Process   76358777 5367493319     759413   66953170
            Cache misses          0          -          -          -
                    Fast     110151   10095563         74      13479
               Auton/SSE          0          0          0          0

    Protocol  ARP                 
          Switching path    Pkts In   Chars In   Pkts Out  Chars Out
                 Process     779028   46741694     459708   27582480
            Cache misses          0          -          -          -
                    Fast          0          0          0          0
               Auton/SSE          0          0          0          0

    Protocol  Other               
          Switching path    Pkts In   Chars In   Pkts Out  Chars Out
                 Process        127       7620          0          0
            Cache misses          0          -          -          -
                    Fast          0          0          0          0
               Auton/SSE          0          0          0          0

    NOTE: all counts are cumulative and reset only after a reload.

 

... I notice that almost all the switching is done by process, so I don't know how to work around this.

To put into context.  This switch connect directly or indirectly almost 190 other devices, between switches (2960s, 2950s, 3560, and 3750) and access points.  It is the default gateway for a lot of VLAN and directly connect our WAN access. 

The switch is running IOS 12.2(58)SE2.  I have red that in other post (lik this one https://supportforums.cisco.com/discussion/11628666/cisco-3750x-24se-12258se2-cpu-utilization-high) that it's advice to to downgrade to 12.2(55)SE8 for stability reason, but this post is 3 years old so I'd like to know if this remains as a valid solution or is another preferable IOS version to work around this problem.

From the "show proc cpu" command I can see other 2 proccess eating CPU resource, HULC LED and Spanning Tree, but I'd like to troubleshoot the IP Input one first, cause is the top most one.

Please, advise for where should I look for solving this problem.

Thanks very much.

30 Replies 30

Hi yusuf habibi,

I already correct that, as Mark Malone pointed that out earlier in this post. Anyway, this didn't made IP Input process to decrease.

 

Thanks

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