Re: Communities

[alex () yuriev com]

> > This seems to need quite some engineering work. :-)
>
> I've thought about this before.
>
> Let's say that I have a DS3 to 701 and a 4xDS1 to 7018.  I might
> sell a DS1 to NetX, and advert their routes[1] to both upstreams.
> If I sell a 15Mbps frac-DS3 to NetZ, I'd better use my 7018
> connection for backup only on their routes.

Router (A) policy 701
Router (B) policy 7018
Router (C) your policy ( 701 && 7018 && whatever else you have)

Where is the problem again? We, Netaxs, (AS4969) do this in multiple
locations with multiple OC-12s to different transit providers and our own
network where some customers want to always use a specific path or not use
any path at all, while the others do not want to be bothered about which
path can be used. That is all done today with Cisco and Juniper gear and
confederations, without need for any random changes to BGP protocol.

> > On a side note, A's possibilities of influencing inbound routing
> > decisions - given that B acts on communities set by A, like `Prepend own
> > ASN a few times before sending over just this link' or `Don't announce
> > to D at all' - are already technically possible.  Frankly, if I were B
>
> Correct.  And a few upstreams allow this.

It is very simple to do. Create a set of 'advertise-me' communities and
'pad-me' communities.


Alex