Agg ports not working correctly after Switch Reboot

[jlock8191]

Good morning,

I am new to the Meraki side of things. We noticed a WAP only negotiating at 100mbps. Due to this, I decided to start with a simple switch reboot. 

After the reboot of switch 1, switch 2 and 3 went down as well due to them getting their feed from Switch 1. 

I waited awhile, but switch 2 never came up, which leads to switch 3 not coming up.

I eventually cycled the ports manually and got switch 2 up, however I believe I may have messed something up. Since I manually toggled the physical ports, the agg config is barking at me. Mentioning "port running LACP and LACP has disabled this port"

I did the same thing between switch 2 and 3 which is giving the same error on its downlink port to switch 3.

Switch 3 is giving occasional "DNS mismatch" messages. Not consistently, but it is definitely having issues keeping clients connected.

Any enlightenment on what I messed up would be amazing. 

Thanks!

[alemabrahao]

There is no point in physically changing the port if you have not configured the new ports as LACP. I advise you to return the ports that were being used before to reestablish the connection and then configure the desired ports for LACP.

https://documentation.meraki.com/MS/Port_and_VLAN_Configuration/Switch_Ports

[jlock8191]

Apologies, I never changed the ports, we are still using the same 2 ports for the agg port. When switch 2 wouldn't come up, I cycled the agg ports individually and was curious if that might have caused this issue. 

I do have a ticket in but figured I would see if the community might have some ideas in the meantime.

Thanks!

[cmr]

If you look at the change log, does it look like anything else changed?  Are the aggregated ports still the same at each end of the link?

[alemabrahao]

Also change the cables, if you noticed a difference in speed it could be a cabling issue.

Otherwise, I advise you to open a support case.

[GIdenJoe]

If you get the actual error that LACP disabled the port you may have following causes:
- Your aggregate members are not going to the same peer switch (common cabling issue).
- One link has a different property (for example if one link negotiates to 100 Mbps while the other goes to 1000 Mbps.
- You have a weird issue where the peer switch is not aware of LACP and is forwarding those LACPDU's to other switches and your main switch sees other peer switches due to this and quickly disabled the port to avoid loops.

I believe from the multitude of errors you are getting I have to assume there is something wrong with which link is connected to which other link.

[jlock8191 · Accepted solution]

Hi all! I just wanted to add that this is resolved. I believe cycling the ports individually messed up the agg ports. After recreating the agg ports from the bottom up, the issue is now resolved. Thanks everyone for your replies!

[cmr]

@jlock8191 I think this new firmware might be for you...

https://community.meraki.com/t5/Switching/New-MS-16-8-stable-firmware-multiple-LACP-and-PoE-fixes/m-...