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

[Jonny Martin]

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.