cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
1588
Views
0
Helpful
5
Replies

C3850's delay is high

tianwen.zhao
Level 1
Level 1

Hello everyone,

We have a cisco 3850 which version is 03.07.04.E

I have found that the delay is so high when I telnet 10.80.1.241 . And I knock to command being delay.But at the same time other switches' delay is normal except 10.80.1.241 . after a while it recovery to normal.

 

ping form switch:

c3560#ping 10.80.1.241

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.80.1.241, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 9/142/218 ms


c3560#ping 10.80.1.242

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.80.1.242, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/5/9 ms

 

 

Abnormal:
C:\>ping 10.80.1.241

Pinging 10.80.1.241 with 32 bytes of data:
Reply from 10.80.1.241: bytes=32 time=85ms TTL=255
Reply from 10.80.1.241: bytes=32 time=47ms TTL=255
Reply from 10.80.1.241: bytes=32 time=124ms TTL=255
Reply from 10.80.1.241: bytes=32 time=22ms TTL=255

Ping statistics for 10.80.1.241:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 22ms, Maximum = 124ms, Average = 69ms

 

Normal:

C:\>ping 10.80.1.241

Pinging 10.80.1.241 with 32 bytes of data:
Reply from 10.80.1.241: bytes=32 time=1ms TTL=255
Reply from 10.80.1.241: bytes=32 time=2ms TTL=255
Reply from 10.80.1.241: bytes=32 time=2ms TTL=255
Reply from 10.80.1.241: bytes=32 time=1ms TTL=255

Ping statistics for 10.80.1.241:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 1ms, Maximum = 2ms, Average = 1ms

 

 

 

I think the circuit is normal and the C3850 seem to normal too ,because other functions work properly.

 

I would appreciate any help.

Thanks you

 

 

 

1 Accepted Solution

Accepted Solutions

 

Have you checked the processor while it was delayed? If not, please look at the output of show proc cpu history. We were having similar issue recently with 3850s, a stack of 7, and the cpu utilization was close to 100% at the time we experience the delay and some packet drops. The main processes which were consuming most of the cpu were SISF Switcher Thread and SISF Main Thread. The processor load usually goes away when we either disabled dhcp snooping completely (removed all dhcp snooping related commands from the switch) or did limit the dhcp snooping to one vlan (eg. ip dhcp snooping vlan 2).

 

HTH,

Meheretab

HTH,
Meheretab

View solution in original post

5 Replies 5

luis_cordova
VIP Alumni
VIP Alumni

Hi @tianwen.zha,

 

You could make a trace to the addresses you show to verify the path the packets take to the destinations.

 

Regards

thank you for your reply
there is only one hop , C3850 is the gateway and the delay is high, thank you

 

Have you checked the processor while it was delayed? If not, please look at the output of show proc cpu history. We were having similar issue recently with 3850s, a stack of 7, and the cpu utilization was close to 100% at the time we experience the delay and some packet drops. The main processes which were consuming most of the cpu were SISF Switcher Thread and SISF Main Thread. The processor load usually goes away when we either disabled dhcp snooping completely (removed all dhcp snooping related commands from the switch) or did limit the dhcp snooping to one vlan (eg. ip dhcp snooping vlan 2).

 

HTH,

Meheretab

HTH,
Meheretab

Thank you for your reply , I will double check what you said when it happened next time.

Hello,

 

on a side note, what is the uptime of the switch (sh ver) ? Sometimes long uptimes (>1 year) can cause devices to respond slowly...

Getting Started

Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community: