My new BGP book: 'Internet Routing with BGP' by Iljitsch van Beijnum BGPexpert My BGP book from 2002: 'BGP' by Iljitsch van Beijnum

Home · BGP Expert Test · What is BGP? · BGP Vendors · Links · Archives · Books · My New BGP Book

BGP (advertisement)
32-bit AS numbers (posted 2005-12-11)

I wanted to write something about 32-bit AS numbers. But Geoff Huston pretty much said it all.

Note however, that at the time of this writing 33580 AS numbers have been assigned by the RIRs. So there are still nearly 31000 available in the IANA global pool and in the RIR's pools combined. The 32-bit AS number capability should show up in routers fairly soon. It turns out that for routing protocols the IETF has more strict rules about publishing RFCs: there must be two interoperating implementations before the RFC may be published. This makes no sense whatsoever (but has that stopped the IETF before?) because this means there is no long-term document for these implementers to work off of, as the drafts (the stage before something becomes an RFC) are removed after 6 months.

The 32-bit AS number draft (called "as4bytes", which is strange as the IETF never uses "byte" but rather "octet", after all 25 years ago there were computers that used "bytes" that weren't 8 bits). As I was saying, the 32-bit AS number draft has been around since at least the year 2000, but it couldn't progress because of the two implementations rule. Turns out that Juniper and Redback actually did implement the draft without telling anyone. When this was discovered the RFC publication process was put into motion. I'm interested to see how long it takes for the RFC to become available.