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Re: Service Provider Exchange requirements
From: John Fraizer <nanog () EnterZone Net>
Date: Mon, 23 Oct 2000 12:04:43 -0400 (EDT)

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.
                                      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

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