[1256] in North American Network Operators' Group
Re: Sprint BGP filters in 207.x.x.x?
daemon@ATHENA.MIT.EDU (Dave Siegel)
Wed Dec 13 14:18:45 1995
From: Dave Siegel <dsiegel@rtd.com>
To: cook@cookreport.com
Date: Wed, 13 Dec 1995 11:57:41 -0700 (MST)
Cc: dmbarton@mci.net, smd@chops.icp.net, freedman@netaxs.com, nanog@merit.edu
In-Reply-To: <Pine.SUN.3.91.951213110855.11239E-100000@tigger.jvnc.net> from "Gordon Cook" at Dec 13, 95 11:17:40 am
> MCI aggregates all its customer's routes into /19's. We have just
> received our first block of address space from the 207.x.x.x range. If
> you continue to filter at /18's for the 207.x.x.x range, you won't be
> able to reach all of MCI's customers.
>
> Needless to say MCI would appreciate it if you'd change your policy to be
> /19's, and I'm sure Sprint's customers would appreciate it as well.
> ==========
> Aside from what Daniel says about Sprint and MCI's routing policy
> mismatch, this statement is interesting on another level. For Dan says:
> MCI aggregates all its customer's routes into /19's. This is new is it
> not? Also it says *MCI* does the aggregating and not the customer.
That may hold true internally, however, I suspect that externally, they
announce only /16's or /15's. Of course, I could be wrong.
What I see right now, is only one announcement from the 207 block...a /19
coming from netaxs, and then some customer of PSI is announcing 5 or so
/24's in the 208 block!
> Would someone please explain how this differs from what I understand to
> be Sprints policy which says (i believe) that it is the CUSTOMER's
> responsibility to aggregate the routes they present to sprint???
Sprint already proxy-aggregates for many of their customers. Most of them
probably don't realize it. It doesn't even affect most of them.
> Why would MCI do the aggregating? Is such mci policy good for mci or
> good for the customer or equally good for both?
Depends on the situation as to whether it's detrimental. Proxy-aggregation,
as this is called, can alter traffic patterns in dual-homed situations. The
change is not always bad, though it is often un-desirable.
In general, proxy-aggregation is good for everybody.
Dave
--
Dave Siegel President, RTD Systems & Networking, Inc.
(520)623-9663 Network Engineer -- Regional/National NSPs (Cisco)
dsiegel@rtd.com User Tracking & Acctg -- "Written by an ISP,
http://www.rtd.com/~dsiegel/ for an ISP."
