Port Bounce Cause

[Richard Pidcock]

We had a port bounce this morning that caused a very brief outage to one of our voice hosts.  Does anyone know how to glean any additional technical information as to why this port bounce happened.

Dec 13 08:07:25.133 CST: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet1/0/3, changed state to down
Dec 13 08:07:26.145 CST: %LINK-3-UPDOWN: Interface GigabitEthernet1/0/3, changed state to down
Dec 13 08:07:29.149 CST: %LINK-3-UPDOWN: Interface GigabitEthernet1/0/3, changed state to up
Dec 13 08:07:31.160 CST: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet1/0/3, changed state to up

Thanks in advance.

[matthew2587 · Accepted solution]

This link will give some reasons as to why this might be happening, and commands to help gather more information.

https://www.cisco.com/c/en/us/support/docs/switches/catalyst-9500-series-switches/218397-troubleshoot-port-flaps-on-catalyst-9000.html#:~:text=A%20port%20flap%2C%20usually%20referred,to%20other%20link%20synchronization%20issues.

[balaji.bandi]

if that is only 1 Port gone up and down.

Different reasons :

1. device rebooted

2. patch may be removed and loose contact

3. check the physical connections.

4. check on the device also connect to that port anything wrong ?

if all the ports are going same status, what model of switch and what IOS code running ?