Recently in Security Category

As Iran celebrates the anniversary of the 1979 Islamic Revolution, it seems like an opportune time to look in on the evolving state of their Internet connectivity. When we last looked, after the disputed elections in June 2009, the picture was one of uneasy stability: logically diverse but physically constrained transit via the United Arab Emirates, backup transit via Turkey. Today, a third way out of the bottle is visible in the routing table: substantial amounts of Internet transit have materialized through a Russian provider. And there, in those obscure entries in the global Internet routing table, may lie echoes of Iran's larger geopolitical strategy.

As our faithful readers know, Renesys monitors routing on the global Internet in real time and uses that information in a variety of ways. For example, we can instantly let you know which networks a hurricane has disabled or even tell you when a war has left things pretty much as they were. In short, we keep an eye on the Internet, the entire Internet, but this is all done at the level of IP addresses and the paths they follow.

The recent attack on Twitter got us thinking. Maybe we should be keeping an eye on a few more things? While your IP addresses and routes to them might be completely stable, the average user doesn't know about those. In other words, when was the last time you typed ...
    http://216.239.59.104
instead of ...
    http://www.google.com
into your browser?

What if someone manages to point your domain name to some other IP addresses? You would still be operational as far as the Internet routers were concerned, but no humans would probably be reaching you. And that's the problem we'll briefly consider in this blog.

When the power goes out to a large part of Brazil, as happened last night shortly after 10pm, it's going to have an impact on telecommunications.

I'm writing this blog entry from the campground at Vermont's beautiful Quechee Gorge, where I took the kids after work. Yes, Renesys is located smack in the middle of some of the nicest hiking, camping, and climbing on earth. No, you shouldn't move here, Northern New England has enough out-of-staters already, thanks. Unless, that is, you are an unusually talented web developer, have worked as a peering coordinator, or know the Internet transit industry inside-out, in which case you should send me your CV, posthaste. thanks, --jim

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Here We Go Again.

Imagine an innocent BGP message, sent from a random small network service provider's border router somewhere in the world. It contains a payload that is unusual, but strictly speaking, conformant to protocol. Most of the routers in the world, when faced with such a message, pass it along. But a few have a bug that makes them drop sessions abruptly and reopen them, flooding their neighbors with full-table session resets every time they hear the offending message. The miracle of global BGP ensures that every vulnerable router on earth gets a peek at the offending message in under 30 seconds. The global routing infrastructure rings like a bell, as BGP update rates spike by orders of magnitude in the blink of an eye. Links congest. Small routing hardware falls over and dies. It takes hours for things to return to normal.

If you put 65 million people in a locked room, they're going to find all the exits pretty quickly, and maybe make a few of their own. In the case of Iran's crippled-but-still-connected Internet, that means finding a continuous supply of proxy servers that allow continued access to unfiltered international web content like Twitter, Gmail, and the BBC.

Seventy-five years ago today, on May 29th, 1934, Egyptian private radio stations fell silent, as the government shut them down in favor of a state monopoly on broadcast communication. Egyptian radio "hackers" (as we would style them today) had, over the course of about fifteen years, developed a burgeoning network of unofficial radio stations. They offered listeners an unfiltered, continuous mix of news, gossip, and live entertainment from low-powered transmitters located in private houses and businesses throughout Cairo.

It couldn't last. After two days of official radio silence, on May 31st, official state-sponsored radio stations (run by the Marconi company under special contract) began transmitting a clean slate of government-sanctioned programming, and the brief era of grass-roots Egyptian radio was over.