Re: AS path weirdness

On 21 Mar 2009, at 02:48, Jason Lewis wrote:

I'm not entirely sure what I'm looking at. The reserved AS, 65490 appears in parentheses and I've never seen that in MRT formatted data and not sure why it's happening.

This has been observed when a vendor runs 32-bit AS aware code on part of their edge, and non-32-bit AS aware code on a different part of their edge.

I'm also not clear on why I see 23456 *and* a 32 bit AS in the path. Is anyone else seeing this or is it something wacky at RRC04? 91.207.218.0/23|29222 6830 (65490) 3356 35320 3.21 23456

There's some history with this prefix. http://www.andyd.net/media/talks/asn4_breaks_network.pdf [from nanog45] Andy