BGP and Macs (Apple Computers.. aka Macintoshs) are really similar i've found. You have to trick both of them into doing what you want them to. With BGP if you arn't using interfaces further away from the source.. they sometimes don't send the right next_hop attribute to their eBPG neighbor. Which is just plain weird. Then not to mention when something suggests you use the next-hop-self command on that neighbor despite it being an eBGP relationship and therefore impossible to do that.. Yeah. Suffice to say, BGP while powerful, is very very fussy about what it will do.