James A. Farrar James.Farrar at
Sun Nov 2 14:30:50 UTC 1997

At 03:53 AM 11/2/97 -0500, you wrote:
>On Sun, 2 Nov 1997, Kirby Files wrote:
>> Can you be a little more precise?  Most providers probably use
>> communities to tag subsets of the routes they carry, and some set of
>> those communities, either through inclusion or exclusion, almost
>> certainly describes the set of customer routes carried by that
>> provider.  (I'm sure this can be stated more clearly.)  GTE certainly
>> does, I'm pretty sure MCI still does, etc.

You are correct.

>What the basic question involved was whether providers have
>some sort of community in place to distribute to customers
>concerning their customer/internal routes.  Also, it would be
>nice if the provider would distribute this information to the
>customer.  Therefore, I was wondering which providers
>had such communities and which providers were willing
>to distribute said communities to customers.
>> Another question is, "Why do you want this info?"  Taking full transit
>> routes from a provider and trying to set localpref or MED based on
>> whether the destination is a customer or peer network?  If you are
>> taking transit, there are good arguments for *not* running
>> default-free.
>It would seem to me to be helpful when coming up with
>policy to route traffic bound for internal/customer
>networks of an upstream to that upstream (unless that link
>is down).  Sometimes the path selection does not allow
>this and we are forced to use foolish kludges like
>as path prepending and other neanderthalic clubbings.
MCI offers announcemnets of:

Backbone Routes
Customer Routes
Customer Routes - w/MED
Full Routes
Full Routes - w/MED

For information on multihoming to MCI:

For information on mulitihoming to MCI and another provider:

Jim Farrar
jfarrar at

>Bradley Reynolds
>brad at
>No Inflated Title
>Internet Access Group

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