As far as I'm aware "a session is configured as IBGP on one end and EBGP on the other end" isn't possible. You can't configure it like that, most of the BGP im

As far as I'm aware "a session is configured as IBGP on one end and EBGP on the other end" isn't possible. You can't configure it like that, most of the BGP implementations I'm familiar with automatically treat the a same-AS neighbor as iBGP and a different-AS neighbor as eBGP. Juniper explicitly has 'internal' and 'external' neighbors, but you can't configure a different peer AS than your own on an internal neighbor or the same peer AS on an external neighbor. BGP sessions also have the AS of the neighbor specified in the local config, and will not bring up the session if it's not what's configured.