loss of access

[mikeos]

I have ms425 as my core and when I add a vlan and vlan interface I have sporadic issues connecting to some devices 

today I added a vlan and the whole network blipped but we did not lose access to anything but users were disconnected from their zoom calls. then an hour later I deleted the vlan as a test to see if it made the same pause on the network 

we noticed that one of our Cisco CUCM phone Cubes lost access to the network and vcenter just was not pingable after that change from certain networks 

to fix it we have to reboot the affected devices

has anyone seen this behavior before 

I have a ticket in with Meraki but so far i'm not getting very far

[cmr]

@mikeos that does seem pretty extreme!  Are your MS425s the spanning tree root for the network and what firmware are you running on them?

[mikeos]

yes my 425's are the STProot and I am running firmware 14.32

[cmr]

14.33.1 is current, but contains the following:

• When an SFP module is inserted/removed on MS420/425 series switches, BPDUs can be delayed leading to STP transitions in the network (predates MS 12)

14.33 includes the following, possibly pertinent fix:

• SVI changes made to stacks may result in incorrect route mappings resulting in packet loss (present since MS 14.31)

I'd definitely go to 14.33.1 and if you can try a beta, it looks like 15.14 resolves the first one.

[mikeos]

it sounds like second option is the problem i am experiencing, so your thinking updating to the most recent should fix this issue

[PhilipDAth]

As @cmr says, that should not be happening.  The current stable firmware release is 14.33.1, so perhaps you could try that in desperation.

Are you using OSPF?

You have access and trunk ports.  I would expect access ports to converge immediately.  It's possible that a trunk port might go into a spanning tree learning state for a while.

Were devices plugged into access ports also affected?

[mikeos]

we are not using ospf on our internal network

my lapto is in an access port and I could not ping the vcenter IP everything else 

if I move my laptop and plug it int another switch that has the same vlan and I plug in there it will work then if I move back to my original connection it won't work super weird

if I tracert it dies on the meraki core

[PhilipDAth]

That's sounding like a firmware bug to me ...