On Thu, Aug 11, 2005 at 08:06:09PM -0400, David Hubbard wrote:

Hi all, I'd appreciate any on or offlist emails with the names of larger providers that allow you, through communities, to do prepending of your AS path to selected remote AS's. We use two providers that allow this since we use the feature but am wanting to dump one of our providers who does not.

I guess cutting to the chase here would be best. I have been collecting BGP community guides for a number of service providers who publically state their BGP communities and their usage. This would include your desired abilities. You can find the collection at: http://www.onesc.net/communities For a quick shameless plug, if anybody has additional community guide locations, big or small, please let me know offlist.

Basically we have a customer within AS X and us and AS X both have transit through AS Y. The link between AS Y and AS X is seriously overloaded so our customer is pretty much dead in the water since AS X is a countrywide monopoly telco for the country in question. We've forced traffic to AS X to take a different route in but since we can't path prepend just to AS X through AS Y, we're stuck with the only solution being disable the link to AS Y or prepend to all of AS Y which we don't want to do. AS Y doesn't feel the need to help since their view is the customer of theirs has chosen to not upgrade the oversubscribed link.

Hrm, sounds like you'd really make out from being able to tell your upstream to surpress the announcements out to that network, provided they aren't a customer of the upstream that is ;-) Keep in mind, if they are a customer the communities, in most cases, will not the results you are looking for. charles