Re: [nznog] Interesting - How a Router's Missed Range Check Nearly Crashed the Internet

On Feb 23, 2009, at 1:00 AM, Skeeve Stevens wrote:

The flaw lay dormant until one of vendor A's systems was deployed in an autonomous system whose ASN, modulo 256, was greater than 250. At that point, the Internet was one typo away from disaster. ... Is this just the 4byte ASN thing from months ago or something new?

This was more a UI feature on the Mikrotiks where AS path prepending was an integer field representing the number of prepends of it's own ASN - rather than the more common approach of providing an actual AS- path to prepend. Cheers, Jonny.