Can some one help me here if I am missing anything to check.


Our Palo Firewall got a vwire configured with interfaces eth1/5 & eth1/6.

eth1/5 is directly connected to eth1/2 of cisco switch and eth1/6 is directly connected to xe-0/0/1 of juniper router.

On switch eth1/2 flappings were observed (below are sample logs which were repeatedly seen for 6 mins) but firewall didn't log port going down, expectation here is firewall should log link down event as its other end of the link was down.

My question here is, are these below logs truly indicate that switch port physically went down or its just saying logical down but not physically down. are they any logs or commands i can run on switch to check whether switch port physically went down or not. On firewall we have this brdagent.log which shows logs for port power detection, do we have anything on switch to identify port power status??

only one interface in port channel and lacp here is in active mode

2021 Dec 01 9:22:06.350 %ETH_PORT_CHANNEL-5-PORT_DOWN: port-channel2: Ethernet1/2 is down

2021 Dec 01 9:22:06.354 %ETH_PORT_CHANNEL-5-FOP_CHANGED: port-channel2: first operational port changed from Ethernet1/2 to none

2021 Dec 01 9:22:06.383 %ETHPORT-5-IF_TRUNK_DOWN: Interface Ethernet1/2, vlan 2856,2959,2961,2975 down

2021 Dec 01 9:22:06.384 %ETHPORT-5-IF_DOWN_INITIALIZING: Interface Ethernet1/2 is down (Initializing)

2021 Dec 01 9:22:10.557 %ETH_PORT_CHANNEL-5-PORT_UP: port-channel2: Ethernet1/2 is up

2021 Dec 01 9:22:11.495 %ETH_PORT_CHANNEL-5-FOP_CHANGED: port-channel2: first operational port changed from none to Ethernet1/2

2021 Dec 01 9:22:11.300 %ETHPORT-5-IF_TRUNK_UP: Interface Ethernet1/2, vlan 2856,2959,2961,2975 up

2021 Dec 01 9:22:11.101  %ETHPORT-5-IF_UP: Interface Ethernet1/2 is up in mode trunk

2021 Dec 01 9:22:20.204 %ETH_PORT_CHANNEL-5-PORT_DOWN: port-channel2: Ethernet1/2 is down
  • Did any answer help you? If so, you should accept the answer so that the question does not keep popping up forever, looking for an answer.
    – Ron Maupin
    Jan 21, 2022 at 15:06

1 Answer 1


From Cisco:

Error Message ETHPORT-5-IF_TRUNK_DOWN: Interface [chars], vlan [chars] down

Explanation: Interface [chars] is trunking, VLANs [chars] are down

Recommended Action The following commands will help determine why this VSAN is down on this interface: show interface, show port-channel internal info interface VLAN, show port-channel internal event-history interface vlan

In other words, your VLANs are down, so the trunk went down, not the physical port.

  • 1
    Thanks for your reference Ron but "ETH_PORT_CHANNEL-5-PORT_DOWN: port-channel2: Ethernet1/2 is down" was indicating 1/2 physically down or 1/2 physically up, to my knowledge it was physically down.
    – Ram Kumar
    Dec 22, 2021 at 15:01
  • If the physical port went down, you'd see something like: %ETHPORT-5-IF_DOWN_LINK_FAILURE: Interface Ethernet1/33 is down (Link failure)
    – Ron Trunk
    Dec 22, 2021 at 15:16

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