Wired Intelligent Edge (Campus Switching and Routing)

New Contributor

VSF and MAD Setup



I think have read enough on 5400 series chassis VSF and MAD setup. But in my view there really is not a lot of good documentation out there. So I going to post one more topic on VSF and MAD - so I can get some help from experts and maybe help others.


I have currently have two - 5412 chassis that I want to setup VSF. I have setup VSF on them and it was pretty straight forward. I am using a 10 Gig DAC cable for VSP between chassis.


Here are my questions:

1. VSF Domain ID - if I am going to have let's say 10 closets with VSF - do I need 10 different Domain ID setup?

     eg. vsf enable domain 1, domain 2, domain 3 .......


2. MAD "assist device" - why is this needed? I know for split-brain purpose but what else?


3. Can I configure VSP without MAD? If so - how do I do this?


4. My current setup is two - 5412 chassis configured with VSF via 10 Gig DAC cable. If I add another - 10 Gig DAC to between the two chassis for redudancy - does this make up for "MAD".


5. I have seen OOBM ports used for "MAD" - can someone share documentation on this - how to setup?


6. Can I do 2930F stacking? If yes - is this also by VSF and having a MAD device setup?


Just have to say - Cisco stacking was so much easier.


Thanks for your help,



Occasional Contributor II

Re: VSF and MAD Setup

Good day,


There is a good document here:



It's about 5400 series in specific.



VSF Domain ID – uniquely identifies VSF system and prevents interfering with other VSF systems; must match with other member to form VSF; configurable;


Basically that is the main and only reason.


You can configure VSF without MAD, it's not recommended although.


MAD is needed when you lose the connection between the two switches. For example, with Cisco, you disconnect the stacking link. MAD device will detect that the vsf stacking link is dead and disable the ports on the slave switch.


Supported VSF Port-types and media

 10Gig fiber

 10Gig DAC

 10Gig copper (SR)

 40Gig DAC


MAD is not obligatory for VSF to work, it's meant to protect against split-brain situations. Yes, you can do 2930F stacking, with the latest firmware version to up to 4 switches.


Look for 2930M modules, which are coming out soon, they will have physical stacking, same as Cisco does.

Occasional Contributor I

Re: VSF and MAD Setup

Here's some help on making the OOBM interfaces your MAD link. 


DEVHOSTNAME(config)# oobm vsf member 1 ip address
DEVHOSTNAME(config)# oobm vsf member 2 ip address
DEVHOSTNAME(config)# oobm vsf member 1 interface enable
DEVHOSTNAME(config)# oobm vsf member 2 interface enable
DEVHOSTNAME(config)# vsf oobm-mad
DEVHOSTNAME(config)# wr mem