[c-nsp] EoMPLS or VPLS loop prevention/storm control

[Nick Hilliard]

On 09/02/2011 15:12, schilling wrote:
> We right now have several bridged campus wide VLAN. It happens several
> times a year where a loop in one of the VLAN will cause our backbone
> to be unavailable. Now we are thinking to better architect the design.
> If we migrate to some platform like ASR9K and use EoMPLS or VPLS, what
> will happen if we have a loop in one of the VLAN?  The simple loop is
> to have a dump switch, connected two ports of it together.

You need to move away from the idea of campus-wide vlans, because that's 
what happens with large open-access L2 networks with loose access controls. 
  Also, you can't fix the problem by extending your L2 network into an MPLS 
core: that will only rearrange the problem to have different failure 
characteristics.

cautionary tale: http://www.cio.com.au/article/65115/all_systems_down/

Nick