Proper way to delete port-channel and associated interfaces

[Tim Buckingham]

I inherited two Nexus 5548 switches with fabric extenders and I'm looking for the proper way to remove port channel group and the associated interfaces which are connected to a server we are repurposing and does need the four connections for etherchannel.

I did remove one of the interface using the "no channel-group" command but it immediately became suspendedbyVPC

version 6.0(2)N2(5)

interface port-channel40
description xxxxxxxxxxxxxx
spanning-tree port type edge

interface Ethernet129/1/31
description xxxxxxxxxxxxxx
shutdown
channel-group 40 mode active

interface Ethernet129/1/32
description xxxxxxxxxxxxxx
shutdown
channel-group 40 mode active

interface Ethernet130/1/12
description xxxxxxxxxxxxxx
shutdown
spanning-tree port type edge
channel-group 40 mode active

[balaji.bandi]

The below steps are good to go :

interface port-channel40

shutdown  (this shutdown of all the members in the port channel)

Default interface Ethernet129/1/31 - this is the interface factory default, and globally, it should be interface shutdown by default in Nexus, check if it is not shutdown

Default interface Ethernet129/1/32

Default interface Ethernet130/1/12

No interface port-channel40  - this removed port-channel 40

[Tim Buckingham]

Thanks, I performed those commands and was able to successfully remove the po40 but I still get suspend by VPC on all those interfaces that were part of the port channel (so I have disabled them for now).

Not sure what I'm missing, and I have down this countless times before (just not on a Nexus stack acting as core).

I considered deleting the configs off those four ports but have not done it yet.

[balaji.bandi]

We would like to see what you are getting suspended for (even though you shut down the physical interface for no reason, I see here). You need to provide the output of what you are seeing on your screen here.

doing 1000's times things will not fix, understand the reason do reasonable steps to fix 

I considered deleting the configs off those four ports but have not done it yet.

If you follow the steps below, the configuration will be the factory default. I am unsure if you have done it; if so, post the output.

Default interface Ethernet129/1/31 - this is the interface factory default, and globally, it should be interface shutdown by default in Nexus; check if it is not shut down

Default interface Ethernet129/1/32

Default interface Ethernet130/1/12

[Tim Buckingham]

I have not done a reset on those interfaces. 

current output:

Ethernet129/1/31 is down (suspended by vpc)
Hardware: 100/1000 Ethernet, address: c07b.bc51.eb60 (bia c07b.bc51.eb60)
Description: xxxxxxxxxxxxx
MTU 1500 bytes, BW 0 Kbit, DLY 10 usec
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA
Port mode is access
auto-duplex, 1000 Mb/s
Beacon is turned off
Input flow-control is off, output flow-control is on
Switchport monitor is off
EtherType is 0x8100

[balaji.bandi]

You'll need to follow all the steps which I suggested.

If you have this in vPC, you need to delete both switches of the pair, not only one of the nexus.

[M02@rt37]

Hello @Tim Buckingham 

I will try a step by step approach. When removing a port channel and its associated member interfaces from your N5548 switch, especially in a vPC setup, care must be taken to avoid creating inconsistencies or causing interfaces to enter an unexpected state like suspendedbyVPC. 

---

Step by step approach:

1.dentify Dependencies and vPC Configuration:
- Verify if the port channel is part of a vPC.

show running-config interface port-channel40
show vpc brief

- If it is a vPC, remove the vPC configuration before proceeding to delete the port channel.

2.Remove Interfaces from the Port Channel:
- Start by removing each member interface from the port channel. Enter interface configuration mode for each and use the no channel-group command:

interface Ethernet129/1/31
no channel-group
no shutdown

- Repeat for all interfaces.

3. Verify Interface State:
- Ensure that interfaces are no longer part of the port channel and are in the up/down or down/down state (depending on whether they are connected to active devices):

show interface status

4.Remove Port Channel Configuration:
- Once all interfaces are removed from the port channel, delete the port channel itself:

no interface port-channel40

5. Clean Up additional configuration, if needed:
- Check for and remove any lingering configuration related to the port channel or interfaces:

no spanning-tree port type edge

6. Verify Configuration:
- Ensure the Po and interfaces are cleanly removed from the configuration:

show running-config interface Ethernet129/1/31
show running-config interface port-channel40

---

 The suspendedbyVPC state occurs because the interface is still considered part of the vPC system, even after removing it from the port channel. Removing the vPC configuration from the port channel ensures a clean removal. better to always ensure no active traffic is flowing through the port channel or member interfaces during this operation.

[Tim Buckingham]

Definitely helpful. Since I already deleted the port-channel (40) it does I get an error when running show running-config interface port-channel40.

I could recreate the port-channel and then follow your process.

[M02@rt37]

@Tim Buckingham 

Please note that moving it from only one switch can lead to mismatched states and residual configuration issues.

So, in order to properly remove a port-channel and its associated interfaces from a Nexus switch with a vPC setup, a systematic and coordinated approach must be followed. This ensures the removal process does not disrupt the stability of the vPC configuration or cause unnecessary errors like suspendedbyVPC. Start by planning the change, including scheduling a maintenance window to minimize impact on production traffic. It’s also critical to save the current configuration on both Nexus switches in the vPC pair to safeguard against any accidental misconfiguration.

The process begins by shutting down all member interfaces of the port-channel on both switches. This ensures no active traffic is traversing these links. Next, remove each member interface from the port-channel group on both switches to decouple them. Once the interfaces have been removed, delete the port-channel configuration itself from both switches. If any interfaces remain in a suspendedbyVPC state, re-enable them by issuing a no shut command. Afterward, validate that the port-channel and its associated configurations have been fully removed from both switches by checking the running configuration and vPC status. Additionally, confirm that no other vPC configurations have been negatively impacted by the removal, ensuring consistency across both switches.

Removing configurations from both switches is essential in a vPC environment, as vPC settings are synchronized between peers. Neglecting to make changes on both switches can result in inconsistencies, which can cause operational issues...