Cisco Nexus 5548 Ethernet 1/5 went down suddenly.

[SanketPatil2481]

Hi, 

There were some issues in the connection on nexus-5548 it was due to the Eth1/5 interface of the cisco nexus-5548 which went down suddenly. The troubleshooting done was to re-seat the optics present on that interface. But, this interface has never been down since its operation started. what could have caused the interface to go down? following is the log on the device,

2020 Feb 8 18:19:24 NEXUS-5548 %ETHPORT-5-IF_DOWN_LINK_FAILURE: Interface Ethernet1/5 is down (Link failure)
2020 Feb 8 18:19:24 NEXUS-5548 last message repeated 1 time
2020 Feb 8 18:19:24 NEXUS-5548 %ETH_PORT_CHANNEL-5-PORT_INDIVIDUAL_DOWN: individual port Ethernet1/5 is down
2020 Feb 8 18:19:28 NEXUS-5548 %ETHPORT-5-SPEED: Interface Ethernet1/5, operational speed changed to 10 Gbps
2020 Feb 8 18:19:28 NEXUS-5548 %ETHPORT-5-IF_DUPLEX: Interface Ethernet1/5, operational duplex mode changed to Full
2020 Feb 8 18:19:28 NEXUS-5548 %ETHPORT-5-IF_RX_FLOW_CONTROL: Interface Ethernet1/5, operational Receive Flow Control state changed to off
2020 Feb 8 18:19:28 NEXUS-5548 %ETHPORT-5-IF_TX_FLOW_CONTROL: Interface Ethernet1/5, operational Transmit Flow Control state changed to off
2020 Feb 8 18:19:28 NEXUS-5548 %ETHPORT-5-SPEED: Interface port-channel56, operational speed changed to 10 Gbps
2020 Feb 8 18:19:28 NEXUS-5548 %ETHPORT-5-IF_DUPLEX: Interface port-channel56, operational duplex mode changed to Full
2020 Feb 8 18:19:28 NEXUS-5548 %ETHPORT-5-IF_RX_FLOW_CONTROL: Interface port-channel56, operational Receive Flow Control state changed to off
2020 Feb 8 18:19:28 NEXUS-5548 %ETHPORT-5-IF_TX_FLOW_CONTROL: Interface port-channel56, operational Transmit Flow Control state changed to off
2020 Feb 8 18:19:38 NEXUS-5548 %ETH_PORT_CHANNEL-4-PORT_INDIVIDUAL: port Ethernet1/5 is operationally individual
2020 Feb 8 18:19:38 NEXUS-5548 %ETHPORT-5-IF_UP: Interface Ethernet1/5 is up in mode trunk

[balaji.bandi]

At this moment as per Log does not show anything wrong, the port went down and after reseat it come back as normal.

You need to Look the OLD Logs when it was completely down, 

This can be below reasons :

1. Someone working nearby pulling the Fibre patch cables.

2. could be a faulty patch lead.

(i have seen kind of issue, mainly physical access around, human errors)

I have good experience and feedback in terms of Nexus 5K, they work as expected as designed, in terms of physical hardware concern. 

If this one kind of occasion in year case, no service outage, ignore it for now ( keep monitoring)

[B.kablawi90]

Hi,

This error message has only two scenarios

1- Cable is disconnected

2- Remote end is shutdown

Below links includes all system error messages of Nexus 5500

Thanks,

Bassel Kablawi

[paul driver]

Hello

sh port-channel summary
sh run int port 51
sh run int eth1/5
sh int eth1/5 transceiver
sh vpc consistency-parameters vpc xx