James Blessing wrote:
Very simply : Would you accept traffic from a customer who insists on sending 0 prefixes across a BGP session?
I just ran through a related issue with one of my upstream peers. It appears that they have a RPF strictly enforced policy, yet during the process of renumbering a customer of a customer from another ISPs space, they were wanting to throw all traffic (our IPs and the other provider's) out to us. It comes down to a simple question of policy, and if you are going to mandate how your customers route proper, valid traffic. I about pulled the plug in my situation, but finally got it sorted out. Thank goodness some routers can allow exceptions to RPF and other providers just use ACLs instead. 0 prefixes is no different than partial prefixes. Asymmetric routing should not be a crime on the Internet because "I don't like it" or "but basic RPF is easier and you're doing something funky anyways". Jack Bates