ms425 loop

mikeos
Here to help

ms425 loop

I have a stack of 6 ms425 as my core and ms250 in stacks in the closet

 

I am connecting my first ms250 to the ms425 

 

I have Aggs on both ends that span switches in the stack

 

when I have 1 cable plugged in everything is fine but I only get 10g throughput and no failover

 

when I plug in the other cable in the agg ports on both ends the ms425 sees it as a loop and ended up crashing my entire stack of 6 ms425's that everything needed the power cycled 

 

I have a ticket open with meraki but they don't believe that the cable I plugged in was the cause of the loop

 

so i'll be doing it again with them this weekend to see it fail in action and maybe figure out why it is happening

 

just wondering if anyone has had this issue

6 REPLIES 6
UCcert
Kind of a big deal

Re: ms425 loop

Hi @mikeos ,

 

Are all your L3 VLAN interfaces configured on your MS425 core?  Is the core configured as your Root Bridge?

 

Switch > configure > switch settings

 

UCcert_0-1620136942371.png

 

Darren O'Connor | uccert.co.uk
https://www.linkedin.com/in/darrenoconnor/

I'm not an employee of Cisco/Meraki. My posts are based on Meraki best practice and what has worked for me in the field.
mikeos
Here to help

Re: ms425 loop

the layer 3 vlans are on the me425 and the core is set as the root bridge

 

this works fine when I use 1 of the cables

 

plugging in the second cable causes the entire thing to fail as it sees it as a loop not an addition to the agg group

I noticed the 12.28.1 firmware update and one of the notes states loop detection on the ms250

 

maybe it's a firmware issue

 

but I figured meraki to meraki would have been a seamless integration

UCcert
Kind of a big deal

Re: ms425 loop

hi @mikeos 

 

Meraki to Meraki generally just works.  I've seen some funnies in the past but have had no major issues over the years.  

 

What version firmware are you running?

 

Are you happy to share screenshots of your uplinks ports on both the 425 and edge?

Darren O'Connor | uccert.co.uk
https://www.linkedin.com/in/darrenoconnor/

I'm not an employee of Cisco/Meraki. My posts are based on Meraki best practice and what has worked for me in the field.
mikeos
Here to help

Re: ms425 loop

We are running 12.28 on everything

 

This is our first Meraki to Meraki setup

The core

mikeos_0-1620140765243.png

 

 

The edge

 

mikeos_1-1620140765253.png

 

 

In this configuration plugging in both edge ports causes a loop and took down a 6 x ms425-32 stack

 

UCcert
Kind of a big deal

Re: ms425 loop

HI @mikeos 

 

On your core AGG/Etherchannels change STP from Loopguard to Rootguard.

 

Also change UDLD to Alert only rather Enforce.

Darren O'Connor | uccert.co.uk
https://www.linkedin.com/in/darrenoconnor/

I'm not an employee of Cisco/Meraki. My posts are based on Meraki best practice and what has worked for me in the field.
mikeos
Here to help

Re: ms425 loop

I did not implement those changes as my meraki ticket said not to at this time

 

I did replace everything yesterday, cables, transceivers

 

I cleaned all the fiber 

 

the connection sat stable for almost 7hours

 

then it just said there was a loop and the connection keeps bouncing there have been 3 other loops detected thruout the night

 

I have turned off that secondary connection for now, 

 

very weird and the only suggestion from tech support is to buy their tranceivers

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