I need a solution for the following situation :
A transit AS with a single internet router.
The router has 2 BGP sessions with international providers and 2 BGP sessions with metropolitan providers. The connections are made without Vlans,on physical Gigabit interfaces.
A client established 2 BGP sessions with the router.One is for international traffic, the second is for metropolitan traffic(to acomplish that used as-path acl). On both connections it advertises the same prefix x.x.x.x /21
The problem is that all the traffic(international and metropolitan) coming into the router(inbound) prefers the Client BGP session for international traffic.
Metropolitan traffic should prefer the metropolitan session. In fact all inbound metropolitan traffic should take the path through the client metropolitan BGP session.
The solution with a second machine for one of the 2 client BGP session is out of the question.
How could this issue be resolved ?
I am waiting for your answers.
A friend told me that with the community attirbute can be done but i dont know how .