CSCvw74609 - ISR4k LACP Configuration lost channel-group X "mode active" gets removed on reload - 4

[wtorres]

Our client has a single cisco ISR4451-X/K9 that was experiencing the bug conditions (channel-group x mode active command loses the "mode active" after a reload) while running 17.3.2.  I just upgraded to 17.3.3 based on the list of fixed versions for the bug and the problem persisted after the reload on 17.3.3 so I had to restore the channel-group x mode active command to restore downstream connectivity to the switch stack below.  Another reason I went with the 17.3.3 is because it is the recommended version for this router.  Can you please provide a version that really fixes the problem that it is also recommended?

[Leo Laohoo]

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@wtorres wrote:

Another reason I went with the 17.3.3 is because it is the recommended version for this router.

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Cisco moves those "star" all the time.  If a "star" version gets overwhelmed with TAC cases, the star gets moved to another version which has the least.  

Raise a TAC Case and make sure there is console access to the router.  TAC needs to see this bug in action.  

[wtorres]

I understand the Cisco changes the "star" version all the time and that was not the only reason we selected it.  The main reason I selected the version was that the but report stated that 17.3.3 fixed the issue which is not the case as the issue is still there in 17.3.3.  Unfortunately, we are not able to take down the router again as it is a production site to show the bootup process to TAC.

The question I have it that the bug report shows the fixed version as 17.3(3.1) so I ask if this is a special Engineering release that is not available yet on the Cisco web site?

[Leo Laohoo]

There is a "worrying" trend in Cisco where information in Bug IDs are either confusing, inaccurate, unreliable and just plain "nuts" (or all of the above).  

I have stopped trusting information found in Bug IDs because of this. 

If anyone wants the "latest" updates in Bug IDs, raise a TAC Case.

Next, if the information in the Bug ID is correct, 17.3.(3.1), is an internal engineering fix (emphasis:  INTERNAL).  Please observe that "17.5.1a" is mentioned as a possible fixed version.  17.5.1a, a "re-build" of 17.5.1, was publicly released over the weekend.  

Finally, if this router is already in production, then how often does this router reboots?

[wtorres]

Hi all, this particular router running 17.3.3 is now in production and I will have to schedule a reboot during a change window. The main problem with this router was that it was a in a new building in the final phase of construction so it was not yet protected by an UPS so it lost power multiple times and it required restoring the port-channel commands every time it lost power.  Now that its power is protected by an UPS, the chances of a reboot are minimal.

I'm always hesitant to deploy early versions of any train but I will try the 17.5.1a to see if it actually fixes the issue.

[Leo Laohoo]

Don't forget that there is a EEM script which can be used as a workaround.

[wtorres]

Hi all, good news, upgrading the Cisco ISR4451-X/K9 router to 17.5.1a fixed the issue with the port-channel mode commands not being retained after a reboot.  I'm happy we don't need to worry about having to restore the commands manually or through a script.

[Leo Laohoo]

Good to hear. 

NOTE:

17.3.4 is scheduled for release in July 2021.  I am not sure if this bug is fixed by then.  If you have a TAC Case, it is worth asking the TAC engineer to check.