When configure BGP in a SDN product, i saw there is an option to enable "Allow as in", could anyone know what is it!
1 Answer
This is to accept the routes which contains your own AS number. By default such routes are filtered.
If you have a single site and different providers you do not want such routes, because, among other reasons, it could cause a routing loop, or cause your traffic to go through the Internet rather than through your internal network.
But if you announce different networks on different sites then in order to receive routes for your other sites, you need to accept those routes, and so to configure allow AS in