RE: Sprint and peering points

["Deepak Jain" <deepak () ai net>]

Maybe I am mistaken, but I thought route-path selection of equal AS length
prefixes is done by numerical value of the AS or next-hop or something. I
haven't had to worry about that for a while.

My guess is that this provider that is receiving the routes is prepending
from Sprint.

Deepak Jain
AiNET

-----Original Message-----
From: Roy [mailto:garlic () garlic com]
Sent: Sunday, April 01, 2001 1:47 AM
To: deepak () ai net
Cc: nanog () merit edu
Subject: Re: Sprint and peering points



You basically have it correct.

An entity that peers with UUNET and Sprint at a public point would now see

1239 1239 20001
701 20001

This then effectively shifts the load to one of my other transit providers
(701)
instead of splitting it between 1239 and 701.  A worse case is would be if
I
was using 701 for backup and the route was 701 20001 20001.

So by making the change Sprint unilaterally shifts the transit packets from
a
public peering point away from themselves.

What would have been nice is for Sprint to tell its customers it was doing
this.  Then I would have expected the change in inbound traffic flows and
taken
action.  As it was, I opened a trouble report and wasted a lot of time
looking
for a problem.



Deepak Jain wrote:

> I am not exactly clear on the impact. For peers that HAVE private
> interconnections with Sprint, the traffic will still pass to Sprint. For
> networks that only have public interconnections with Sprint, Sprint
customer
> traffic will traverse normally as well.
>
> The networks that fall outside of this category are networks that you
don't
> have a direct customer connection with, which are choosing amongst your N
> available transit providers to pass traffic to you. If any of these
networks
> had a private interconnect with Sprint, there would be no effect.
>
> So, if I logic'd this out correctly, the networks that are affected HAVE
> peering with Sprint, but ONLY at public access points. I'm assuming this
is
> really significant to your traffic flow. What would Sprint notifying you
of
> this change do for you?
>
> Deepak Jain
> AiNET
>
> -----Original Message-----
> From: owner-nanog () merit edu [mailto:owner-nanog () merit edu]On Behalf Of
> Roy
> Sent: Saturday, March 31, 2001 11:22 AM
> To: nanog () merit edu
> Subject: Sprint and peering points
>
> Since I am located in what PacBell thinks is a rural area, I have to
contend
> with using multiple T1s.  This forces me to play with the AS paths in
order
> to load balance between my upstreams (Sprint and others)
>
> I have found that Sprint is prepending their AS when sending routes to
many
> of the public exchanges (example "1239 1239 20001") in order to "shift
load"
> to private peer connections.
>
> The result is that now my other upstreams that send out the normal "701
> 20001" get the brunt of the traffic from the public exchange points.
>
> Needless to say I am a bit pissed at Sprint for doing this and not telling
> me.  I had been a fan of Sprint until this happened.  Anyone else out
there
> seeing the same problems?  Any ideas on how to cure it
>
> Roy Engehausen