In the “internet meltdown” post I’ve described the main reason for the routing problems we’re experiencing in the Internet: everyone wants to be truly multihomed. All these end-customers obviously need their own AS number and it’s no wonder the experts predict we’ll run out of AS numbers in two to three years.
There’s no need to panic: the technical solution (four byte AS numbers) has been ready for several years … but it’s not implemented yet in majority of Cisco IOS-based platforms. Does that mean we’ll experience Internet-wide problems when the regional registries start allocating AS numbers larger than 65536 in a few months? Luckily, the answer is NO, the new BGP standards are completely backward-compatible … but if you’re a Service Provider, you have to start thinking about the upgrade path.
You can find more answers on this topic
in the article I wrote for SearchTelecom.