Symptom
When attempting to ISSU a Nexus 9000 device when Spanning Tree ISSU conditions fail on the remote vPC peer, the following error message is returned:
N9K-2# install all nxos bootflash:nxos.9.3.3.bin non-disruptive
Do you want to continue with the installation (y/n)? [n] y
Install is in progress, please wait.
Performing runtime checks.
[####################] 100% -- SUCCESS
Notifying services about the upgrade.
[# ] 0% -- FAIL.
Return code 0x401E0065 (request was aborted by service).
Please issue "show install all failure-reason" to find the cause of the failure.
Install has failed. Return code 0x401E0065 (request was aborted by service).
Please identify the cause of the failure, and try 'install all' again.
`show install all failure-reason`
Service "vpc" returned error: STP ISSU preupgrade check failed - Upgrade needs to be disruptive! (0x40DD0048)
Conditions
This error message is returned when the remote vPC peer of the Nexus device being ISSU'd fails one of the Spanning Tree Protocol ISSU conditions. To view additional details about which Spanning Tree Protocol ISSU condition did not pass on the remote vPC peer, the `show spanning-tree issu-impact` commands needs to be executed on the remote vPC peer.
Workaround
Resolving the issues highlighted by the `show spanning-tree issu-impact` command executed on the remote vPC peer will allow the ISSU to continue.
Further Problem Description
This software defect tracks enhancements made to the output of the `show install all failure-reason` command after an ISSU upgrade fails due to a failed Spanning Tree Protocol ISSU condition on the remote vPC peer so that it is more clearly actionable by the end user.
