[ NNSquad ] Re: Peering dispute cuts off Sprint<->Cogent Internet traffic

[Kevin McArthur <kevin@stormtide.ca>]

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: nnsquad-bounces+george_ou=lanarchitect.net@nnsquad.org
[mailto:nnsquad-bounces+george_ou=lanarchitect.net@nnsquad.org] 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 <edward.jankiewicz@sri.com>
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