MVRP Global - Issues with other VLANs

[kris]

Hello

im having an issue that i would like to put to the community before i log a ticket with TAC

I have a customer who has some audio gear that needs AVB and MVRP enabled to function. 

The customer has some 9300's with the appropriate licensing. They have three switches, one of them acting as the layer3 device to the rest of the network and 2 9300 edge switches. 

When i enable MVRP Global on the switches im finding that normal VLAN traffic does not pass between the switches and to get traffic flowing again i need to issue "no mvrp" on the trunk interface. 

As this is a shared audio and corporate data/VLAN switch I'm concerned that i won't be able to have MVRP dynamic VLANs and corporate VLANs flowing across the three switches

I have also noticed that DHCP for devices connected to the Trunk ports stops working. Access ports on the same vlan get DHCP leases without issue. 

[Flavio Miranda]

On the 9300 documentation there´s a warning about MVRP:

"VTP should be in the disabled mode or transparent mode for MVRP to work. "

[kris]

Hello 

Thanks, i have disabled VTP before enabling the MVRP VLAN create command 

[Flavio Miranda]

Another warning:

"Running MVRP and REP together may block a port (with all VLANs being pruned on the port) and this can cause blocking of a segment port out of REP control. This can cause REP to lose control on the convergence of such a traffic. MVRP may introduce some delay for traffic recovery after REP reconvergence. You can disable MVRP to achieve fast reconvergence when REP is also used. "

[kris]

Thanks but Im not using REP either 

[kris · Accepted solution]

Hi All

With the help of Cisco TAC we got to the bottom of this. 

With MVRP Global enabled, all existing VLANs must be registered/declared by the switches.

To register / declare existing Corporate/Non MVRP created VLANs you need to create an SVI. An existing VLAN in the VLAN databse is not enough.

Example:

vlan 100

name DATA

interface vlan 10

no ip address

a few other quick tips to help out. with MVRP Global enabled the switch will expect a MVRP capable device connected to the other end of all configured trunks. 

eg:

int g1/0/1

switch port mode trunk

to connect a non MVRP enabled switch / wireless access point / other smart but non MVRP enabled switches to trunk ports you need to use the "mvrp registration fixed" command on the trunk interface.

eg: 

int g1/0/1

switch port mode trunk
mvrp registration fixed

hope this helps anyone else in the same boat.

[David Mowery]

This saved my bacon today. Thank you