BGP community

Hello all, again.

As the topic suggests, I would like to talk about bgp communities and how to best deploy them.

Let's say, I have (A)66.66.66.0/24 and (B)69.69.69.0/24. Now, both originates at a router and both are announced to the internet.

"A" is used for providing internet and "B" is used for providing some special peering of sorts for services that are hosted locally (CDN's).

Traffic for "A" is metered and "B" runs amuck, getting as much bandwidth as possible (for the client).

Before you scratch your head and wonder why, let me say it's a situation I'm not happy with and not much can be done about it.

So, some clients are peered via bgp and most are on static. The problem arises when a clever client decides to route traffic through peer "B" in hopes of stealing free internet; they can because both IP are present on the routing table.

So how would anybody use bgp community to stop community 65534:1235 from going to the internet?

Firstly the community has to be tagged on the inbound? They aren't really routes since they are directly connected. Am I right in assuming that I have to go full bgp peers with clients?

I don't mind criticism, as long as I learn and get what I need.

I'd appreciate any help. Thank you