Upstreams blocking /24s? (was Re: How Not to Multihome)

Mon Oct 8 23:06:52 UTC 2007

Hi,

On Oct 8, 2007, at 2:48 PM, Scott Weeks wrote:
> However, if it's less than a /24 it won't get very far as most  
> upstreams block prefixes longer than a /24.

I'm curious: a couple of people have indicated they do not believe  
this to be the case. Anybody have any hard data on what filters are  
actually in use today?

Others have indicated that such filters (assuming they exist) will  
not last in the face of paying customers presenting longer than /24  
prefixes for routing.  Specifically, that ISPs will relax their  
filters (allowing longer than /24) in order to get their peers to  
accept their long prefixes.  Anybody have an opinion on the  
likelihood of this?

Thanks,
-drc