Quick Scenario -1 – Bgp Communities – (no-export)
Aug 10
Uncategorized bgp, ccie, ccna, ccnp, cisco, jncie, jncip, jncis, juniper, ldp, mpls, no-advertise, ospf, rsvp No Comments
Hi,
This will be a series of posts in which i shall be posting some quick scenario labbings. Mostly i have designed these so that I can relate to some stuff which i do not often use, nevertheless will blog all small topics
Community – No-export
“NO-EXPORT is commonly used within an AS to instruct routers not to export a prefix to eBGP neighbors. For instance, subnets of a larger block can be advertised to influence external AS best-path selection, and those not required for this traffic engineering purpose may be tagged NO-EXPORT to prevent them from being leaked to the Internet (and thus contributing to unnecessary global routing table growth). If a neighboring AS accepts this community, it can be used to selectively leak more specifics for traffic engineering but limit their propagation to just one AS.”
Requirement – R1 has its loopback advertised to R3 via BGP. Make sure the advertisement stays within the AS and should not go to another AS Router in this Case R3
Before community addition – Routing Table of R3
AS we can see below route is not seen R3.
Regards
Rakesh M