Re: Reason for Bandwidth change in N9K-C9396PX

ArvindSoni3117 · ‎07-05-2020

Hi,

this is nexus 9K series switch which is connected to same its peer 9K series switch with 10G link speed.

Now for some reason port went down and came up. with the below logs its shows bandwidth change from 100000Kbit to 10000000Kbit. I am sure no one has change the bandwidth between the switches.

is this normal behavior of switch, switching its BW from 1G to 10G in port status transition from down to up.

i would like to understand reason behind the same. Kindly help.

corp7-n9k-cr-1# sh log | i Jul
2020 Jul 3 01:00:34 corp7-n9k-cr-1 %ETHPORT-5-IF_BANDWIDTH_CHANGE: Interface port-channel4024,bandwidth changed to 100000 Kbit
2020 Jul 3 01:00:34 corp7-n9k-cr-1 %ETHPORT-5-IF_BANDWIDTH_CHANGE: Interface port-channel4025,bandwidth changed to 100000 Kbit
2020 Jul 3 01:00:34 corp7-n9k-cr-1 %ETHPORT-5-IF_BANDWIDTH_CHANGE: Interface port-channel4023,bandwidth changed to 100000 Kbit
2020 Jul 3 01:38:13 corp7-n9k-cr-1 %ETHPORT-5-IF_BANDWIDTH_CHANGE: Interface port-channel4025,bandwidth changed to 10000000 Kbit
2020 Jul 3 01:38:25 corp7-n9k-cr-1 %ETHPORT-5-IF_BANDWIDTH_CHANGE: Interface port-channel4023,bandwidth changed to 10000000 Kbit
2020 Jul 3 01:38:25 corp7-n9k-cr-1 %ETHPORT-5-IF_BANDWIDTH_CHANGE: Interface port-channel4024,bandwidth changed to 10000000 Kbit

satish.txt1 · ‎04-04-2022

I am seeing same issue and also noticed my HP 6120XG switch connected with Cisco Nexus 9396PX in vPC (LACP) also going down during that issue.

2022 Mar 31 05:28:39 swt-phx-k006-leaf-2-2 %ETH_PORT_CHANNEL-5-FOP_CHANGED: port-channel412: first operational port changed from Ethernet1/3 to Ethernet1/4
2022 Mar 31 05:28:39 swt-phx-k006-leaf-2-2 %ETH_PORT_CHANNEL-5-PORT_DOWN: port-channel412: Ethernet1/3 is down
2022 Mar 31 05:28:39 swt-phx-k006-leaf-2-2 %ETHPORT-5-IF_BANDWIDTH_CHANGE: Interface port-channel412,bandwidth changed to 10000000 Kbit
2022 Mar 31 05:28:39 swt-phx-k006-leaf-2-2 %ETHPORT-5-IF_DOWN_INITIALIZING: Interface Ethernet1/3 is down (Initializing)
2022 Mar 31 05:28:40 swt-phx-k006-leaf-2-2 %ETH_PORT_CHANNEL-5-FOP_CHANGED: port-channel412: first operational port changed from Ethernet1/4 to none
2022 Mar 31 05:28:40 swt-phx-k006-leaf-2-2 %ETH_PORT_CHANNEL-5-PORT_DOWN: port-channel412: Ethernet1/4 is down
2022 Mar 31 05:28:40 swt-phx-k006-leaf-2-2 %ETHPORT-5-IF_DOWN_PORT_CHANNEL_MEMBERS_DOWN: Interface port-channel412 is down (No operational members)
2022 Mar 31 05:28:40 swt-phx-k006-leaf-2-2 %ETHPORT-5-IF_BANDWIDTH_CHANGE: Interface port-channel412,bandwidth changed to 100000 Kbit
2022 Mar 31 05:28:40 swt-phx-k006-leaf-2-2 %ETHPORT-5-IF_DOWN_INITIALIZING: Interface Ethernet1/4 is down (Initializing)
2022 Mar 31 05:28:40 swt-phx-k006-leaf-2-2 %ETHPORT-5-IF_DOWN_PORT_CHANNEL_MEMBERS_DOWN: Interface port-channel412 is down (No operational members)
2022 Mar 31 05:28:49 swt-phx-k006-leaf-2-2 %ETH_PORT_CHANNEL-5-PORT_SUSPENDED: Ethernet1/3: Ethernet1/3 is suspended
2022 Mar 31 05:28:50 swt-phx-k006-leaf-2-2 %ETH_PORT_CHANNEL-5-PORT_SUSPENDED: Ethernet1/4: Ethernet1/4 is suspended
2022 Mar 31 06:05:19 swt-phx-k006-leaf-2-2 %ETHPORT-5-IF_DOWN_LINK_FAILURE: Interface Ethernet1/3 is down (Link failure)
2022 Mar 31 06:05:19 swt-phx-k006-leaf-2-2 %ETHPORT-5-IF_DOWN_LINK_FAILURE: Interface Ethernet1/4 is down (Link failure)

Sergiu.Daniluk · ‎04-06-2022

It's expected since there are no more active interfaces in the port-channel. It goes to the lowest supported bw, which is 100M.

Stay safe,

Sergiu