Nexus switch port is flapping

[BorislavPenchev0962]

Hi,

there are 4 nexus switches 5596, and problem is only on Switch00-01.

a port 2/8 towards firewall is flapping every few hours, causing disconnects.

This is a sync failure state port which forces the firewalls to do a failover,

when it fails and cause interrupts because of hardware limitation on their side the port is failing and causing the above situation.

found no errors on the firewall /connected environment.

IOS version 7.1(3)

no input/output errors on the switch port, only link failure messages.

replaced cables to that port and moved it to another switch, which seems to have solved a bit the problems.

how may we find any indications on faults or if this situation can happen in the future.

2022 Jul 1 08:07:58 Switch00-01 %ETHPORT-5-IF_DOWN_LINK_FAILURE: Interface Ethernet2/8 is down (Link failure)
2022 Jul 1 08:08:01 Switch00-01 %ETHPORT-5-SPEED: Interface Ethernet2/8, operational speed changed to 1 Gbps
2022 Jul 1 08:08:01 Switch00-01 %ETHPORT-5-IF_DUPLEX: Interface Ethernet2/8, operational duplex mode changed to Full
2022 Jul 1 08:08:01 Switch00-01 %ETHPORT-5-IF_RX_FLOW_CONTROL: Interface Ethernet2/8, operational Receive Flow Control state changed to off
2022 Jul 1 08:08:01 Switch00-01 %ETHPORT-5-IF_TX_FLOW_CONTROL: Interface Ethernet2/8, operational Transmit Flow Control state changed to off
2022 Jul 1 08:08:01 Switch00-01 %ETHPORT-5-IF_UP: Interface Ethernet2/8 is up in mode access
2022 Jul 1 08:23:49 Switch00-01 %ETHPORT-5-IF_DOWN_LINK_FAILURE: Interface Ethernet2/8 is down (Link failure)
2022 Jul 1 08:23:53 Switch00-01 %ETHPORT-5-SPEED: Interface Ethernet2/8, operational speed changed to 1 Gbps
2022 Jul 1 08:23:53 Switch00-01 %ETHPORT-5-IF_DUPLEX: Interface Ethernet2/8, operational duplex mode changed to Full
2022 Jul 1 08:23:53 Switch00-01 %ETHPORT-5-IF_RX_FLOW_CONTROL: Interface Ethernet2/8, operational Receive Flow Control state changed to off
2022 Jul 1 08:23:53 Switch00-01 %ETHPORT-5-IF_TX_FLOW_CONTROL: Interface Ethernet2/8, operational Transmit Flow Control state changed to off
2022 Jul 1 08:23:53 Switch00-01 %ETHPORT-5-IF_UP: Interface Ethernet2/8 is up in mode access

[balaji.bandi]

is this ever worked ? this was seen only recently (and was working stable before)

what is other side connected device ( i mean what FW ?)

First check Physical cable 

Move the config to different port and check

post interface config and interface status:

show run interface Ethernet2/8

show interface Ethernet2/8

[Jitendra Kumar]

have you manually configured interface speed and duplex?? if it auto negotiates then change it to manual both devices 

Please share the output show interface command this port

[MHM Cisco World]

I think you need to change port or cable it L1 issue.