George,
In this case however, we're talking major carriers, which have many many
peers (massively multihomed). There are multiple routes around, as
evidenced by the fact that people are using proxying services to get
around the damage at the application layer.
As for BGP propagation, if its following the RFC then the routes are
already advertised and before the peering agreement broke down, they
just happened to be a shorter path. Once that peer dies, it should fall
back to the longer paths in near real-time. (within moments, as soon as
the bad route stops advertising (which it cant do if it cant reach the
other end)) This is a core routing principle of the internet, and how it
is supposed to be tolerant to attacks on infrastructure -- If this
mechanism isn't working, then we have some serious resiliency problems
on critical backbones.
You would have to do something special to stop BGP from rerouting --
like, for example, falsely advertising a route that doesn't work while
making it appear closer than the alternatives. You could also
theoretically block the remaining peers from advertising routes to that
network, but again, that would be a massive net neutrality violation as
they would be actively blocking a pathway, and not simply just not
peering. Essentially, saying if I don't want to peer with you, no one
else can either.
There's more going on here....
Kevin McArthur
George Ou wrote:
There's no violation of any RFCs here, it's a peering dispute which is quite
common on the Internet.
It's a long running myth that routes are automatically rerouted on the
Internet. Unless one of the two end-points is dual-homed with 2 completely
separate ISPs configured for BGP (or DNS remapping), any break in the route
means a disconnection between the two points. Even when BGP does exist, it
takes some time for the routes to propagate so there's always some outage
for a period of time when there's a break in the link.
George
-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of
Barry Gold
Sent: Friday, October 31, 2008 1:38 PM
To: NNSquad
Subject: [ NNSquad ] Re: Peering dispute cuts off Sprint<->Cogent Internet
traffic
From: Ed Jankiewicz <[EMAIL PROTECTED]>
Subject: Total Filtering
As many news organizations are now reporting, Sprint-Nextel (Embarq) has
decided to sever its Internet connection with Cogent, another Internet
service provider. This action has caused a "hole" or "rip" in the
internet, meaning that Sprint-Nextel (Embarq) and Cogent customers may
find they cannot access resources hosted by the other company's
customers. Similar standoffs have occurred in the past, and usually one
company backs down after a few days, but no one can predict what will
happen in this case.
OK, so what has happened to the "treats censorship as damage and routes
around it" Internet? Even if Embarq and Cogent are no longer talking to
each other, the routers should be automatically finding routes via other
carriers and sending the packets -- around Robin Hood's barn if
necessary, but the Internet is supposed to be _robust_. Jon Postel
designed it that way -- I've read the RFCs. That's what ARPA specified
when they paid for the development of first the ARPANet and later the
Internet -- and what NSF paid for when they branched off NSFNet and
allowed commercial traffic.
Are these guys programming their routers to just drop packets with
certain destination IP addresses, instead of finding the shortest
available route?
I'm beginning to think that Congress (or perhaps an international body
similar to the WTO) should make the core RFCs (IP, TCP, BGP, FTP, HTTP,
SMTP, and RFC 822) have the force of law. And anybody who violates
those protocols should be fined and/or have their connections turned off.
--
Kevin McArthur
StormTide Digital Studios Inc.
Author of the recently published book, "Pro PHP"
http://www.stormtide.ca
