[c-nsp] REP

[sthaug at nethelp.no]

> > I think such rings would be better served by using REP (Cisco) or
> > EAPS(Extreme)
> 
> You've made me curious, so I went and looked what REP is, hoping for
> great innovation - and I find myself somewhat disappointed, it seems to 
> be "something similar to RPVST or MST, just incompatible".
> 
> Since it still disables a port (instead of using all links available 
> in the network, using L2 SPF 'routing', like HP's mesh technology does),
> I can't see an immediate advantage of REP vs. RPVST or MST...?

The fact that REP and EAPS are explicitly *not* compatible with regular
IEEE spanning tree is one of the great attractions of these protocols.
This means that a customer who sends STP traffic into your network can
*not* influence your ring topology/failover.

Additionally, REP and EAPS are explicitly made for a ring architecture,
and can therefore be made simpler and/or converge more rapidly.

We have lots of EAPS rings. It works for us. We might be interested in
using ME3400 with REP for the same type of rings if it had decent CAM
size.  Unfortunately, it doesn't - 8K MAC addresses is uncomfortably
close to the number of MAC addresses we already have in many of our
rings.

Steinar Haug, Nethelp consulting, sthaug at nethelp.no