Interface up/down randomly

[DeanL01]

Dear experts

this port is a member of port-channel,it always shows below message in log,but the other end has no issue.There's no mismatch of speed and duplex on both ends. Anyone could advise why it happens? Thanks a lot!

002437: Jan  6 21:32:30.848 GMT: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/26, changed state to down
002438: Jan  6 21:32:32.794 GMT: %LINK-3-UPDOWN: Interface GigabitEthernet0/26, changed state to down
002439: Jan  6 21:32:38.859 GMT: %LINK-3-UPDOWN: Interface GigabitEthernet0/26, changed state to up
002440: Jan  6 21:32:42.541 GMT: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/26, changed state to up
002441: Jan  6 22:01:47.010 GMT: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/26, changed state to down
002442: Jan  6 22:01:48.965 GMT: %LINK-3-UPDOWN: Interface GigabitEthernet0/26, changed state to down
002443: Jan  6 22:01:55.022 GMT: %LINK-3-UPDOWN: Interface GigabitEthernet0/26, changed state to up
002444: Jan  6 22:01:59.090 GMT: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/26, changed state to up
002445: Jan  7 00:00:49.385 GMT: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/26, changed state to down
002446: Jan  7 00:00:51.339 GMT: %LINK-3-UPDOWN: Interface GigabitEthernet0/26, changed state to down
002447: Jan  7 00:00:59.535 GMT: %LINK-3-UPDOWN: Interface GigabitEthernet0/26, changed state to up
002448: Jan  7 00:01:03.075 GMT: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/26, changed state to up
002449: Jan  7 00:29:41.349 GMT: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/26, changed state to down
002450: Jan  7 00:29:43.303 GMT: %LINK-3-UPDOWN: Interface GigabitEthernet0/26, changed state to down
002451: Jan  7 00:29:51.373 GMT: %LINK-3-UPDOWN: Interface GigabitEthernet0/26, changed state to up
002452: Jan  7 00:29:55.039 GMT: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/26, changed state to up

[luis_cordova]

Hi @DeanL01,

Please, review this other conversation, it can be helpful:

https://community.cisco.com/t5/switching/c3750-stack-lineproto-5-updown-all-three-seconds/td-p/1453670

Regards

[Leo Laohoo]

Look at the time and date. The down/up or up/down are spread too far apart.
Normally I see behaviours like this when computers go to sleep/hibernation or when the user logs out.

[Fulvio Ferreira]

What is the switch model? Did you try to test the copper cables?

If applicable, try to use the following commands to test the cables:

#test cable-diagnostics tdr interface gi0/26
#show cable-diagnostics tdr interface gi0/26