I thought I knew all there is to know about the AS-path prepending before last month’s incident, which prompted me to focus on this particular Cisco IOS feature.
For example, did you know you could do inbound AS-path prepending? I didn’t, until Rodney Dunn from Cisco mentioned it in an e-mail exchange. Did you ever wonder whether the AS-path prepending affects inbound or outbound AS-path filters? I had a hunch it doesn’t, but was never sure.