RFC-4364: PE - CE routing exchange using BGP

["Dilip Kumar" <dilipks at gmail.com>]

Hi All,
    I am implementing RFC-4364 and considering BGP for PE to CE (and vice versa) routing information exchange. Following text from Section-7.4  of the RFC indicates that there is no need to run multiple instances of BGP on PE router.

            "a) Unlike the IGP alternatives, this does not require the PE
               to run multiple routing algorithm instances in order to
               talk to multiple CEs."

As CEs can use overlapping private addresses, it may be possible that two CEs connected to the PE may have the same IP address for BGP. This will allow only one BGP neighbor to be created at PE, unless some other key, like instance ID, is attached along with peer address at PE. I was wondering how it would be possible without running multiple instances of BGP at PE. Can anyone explain/clarify it ?

Thanks,
Dilip