On Sat, Aug 23, 2025 at 7:49 AM Saku Ytti via NANOG <nanog@lists.nanog.org> wrote:
Why do we use distance vector EGP? Why do we advertise prefixes?
Because we like to get paid. The problem with a link-state protocol is that every link in the system is a valid transit for every routed prefix. We can control the link transit costs, prefer some paths over others, but there's no way to express that even though a particular prefix is attached to a node on the other side of this link, we're not under any circumstances permitted to use this link to reach it. As a result, we can only use a link-state protocol in a system where the subscriber has paid for the right to use -all- of the links in the system. Regards, Bill Herrin -- William Herrin bill@herrin.us https://bill.herrin.us/