So Philip Smith / Geoff Huston's CIDR report becomes worth a good hard look today

Dorian Kim dorian at
Thu Aug 14 05:47:20 UTC 2014

On Thu, Aug 14, 2014 at 12:15:36AM -0400, Patrick W. Gilmore wrote:
> Composed on a virtual keyboard, please forgive typos. 
> > On Aug 13, 2014, at 22:59, Suresh Ramasubramanian <ops.lists at> wrote:
> > 
> > Swisscom or some other European SP has / used to have a limit where they would not accept more specific routes than say a /22 from provider x, so if you wanted to take a /24 and announce it you were SOL sending packets to them from that /24 over provider y.
> > 
> > Still, for elderly and capacity limited routers, that might work.
> And Sprint used to filter on /19s outside swamp space. (See NANOG 1999 archives for my [wrong then corrected] interpretation of ACL112.) Etc., etc. 
> For stub networks, especially ones who are not as performance sensitive, this can help extend the life of their routers. But not everyone can make AGS+s work for years past their useful life or get "-doran" IOS builds. The 6500 was first sold in 1999. I'm impressed it has lasted this long, even with new sups. Time to start thinking about upgrading. 

Just as a historical note, Sprint didn't have AGS+ or such equipment that were being propped up by the /19 filters (at least for the vast majority 
of the filter's existence). Neither did Verio. Those filters were primarily an attempt to enforce a certain behavior. 

Also, my recollection is that during that era "named" builds were typically named via receipient's well known email id, e.g."-smd" or first name 
"-sean" and I don't think I've ever seen it named after the last name unless it was their email id as well.


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