Re: Service Provider Exchange requirements

[John Fraizer <nanog () EnterZone Net>]

On Mon, 23 Oct 2000 hardie () equinix com wrote:

> > Why would one use a VLAN in a shared-media exchange?  The only legit
> > reason I can think of is to enforce the "next-hop-self" rule and prevent
> > peer A from exposing direct peer B routes to peer C.
>
> One reason we've looked at is the ability to seperate multicast
> traffic from unicast traffic without having to have seperate physical
> media.  In general, it can be used whenever you want to keep some
> traffic out of the way of other traffic.  Another possible reason
> along those lines for ethernet based exchanges would be allowing jumbo
> frames on some VLAN seperate from the basic shared-media exchange.
>                               regards,
>                                       Ted Hardie

If your switch is MCAST aware, you should be able to keep mcast traffic on
ports tagged for it to begin with.  If your switch isn't mcast aware. you
need to find a new switch.

As for jumbo frames, will someone remind me what the benefit of using a
larger MTU on the edges than you have in the core is?  Is the edge device
going to aggregate 6 1500-byte packets into a single 9000-byte jumbo frame
for me?


---
John Fraizer
EnterZone, Inc