I have completed section 4.x and 11.x and have reachability to all parts of the network except BB1's interface (18.104.22.168) and BGP prefixes that originated from AS 54. I know why there is no reachability and was wondering if a step is missing in the lab. There is no reachability because BB1 does not have either specific routes or a default route pointing back to the internal networks. As far as I can tell, this is due to R6's S0/0/0 interface being passive under RIP. I know this can be solved by advertising a default via BGP or redistributing RIP into BGP to BB1 from R6. Is this allowed?