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[ NNSquad ] Re: Peering dispute cuts off Sprint<->Cogent Internet traffic
As evident in the stories people have posted, we get at least one major peering dispute per year between tier 1 providers and certain pockets are cut off from other pockets. Mind you that it’s not everything cut off for those people; just certain destinations. This is the nature of peering disputes and it results in some temporary breaks in the IP infrastructure. The fact that you can route around it above the IP layer of the OSI model with proxy or DNS tricks is useful to a minority, but not to the majority that is being affected.
BGP propagation is delayed (or dampened) by design. You do NOT want a flapping interface on a single router on the Internet that’s going up and down every few seconds or few minutes to cause a massive ripple of BGP updates throughout the Internet every few seconds or minutes. For this reason, BGP updates are very conservative for good reason and they are designed to ignore temporary failures. Only when the failure is prolonged will the BGP routing update be sent out to the Internet. When the original link comes back online, there is once again a delay on the BGP update because we can’t be sure if the link is just flapping up and down or if it’s permanently back online.
As for the concept of fault tolerance on the Internet, that is a capability of certain portions of the Internet and it must be carefully designed, engineered, and it is a premium feature. Failover is not a default design on the Internet nor should anyone expect it. The concept of auto failure or this massive meshed network on the Internet is largely a myth. Every failover route is by careful design and someone is paying handsomely for that capability.
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.
Sent: Friday, October 31, 2008 1:38 PM
Subject: [ NNSquad ] Re: Peering dispute cuts off Sprint<->Cogent Internet
From: Ed Jankiewicz <firstname.lastname@example.org>
Subject: Total Filtering
As many news organizations are now reporting, Sprint-Nextel (Embarq) hasdecided to sever its Internet connection with Cogent, another Internetservice provider. This action has caused a "hole" or "rip" in theinternet, meaning that Sprint-Nextel (Embarq) and Cogent customers mayfind they cannot access resources hosted by the other company'scustomers. Similar standoffs have occurred in the past, and usually onecompany backs down after a few days, but no one can predict what willhappen 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
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.
StormTide Digital Studios Inc.
Author of the recently published book, "Pro PHP"