Withdrawls and announcements attempt 2

"Justin W. Newton" <justin@erols.com> writes

* Its /a little/ more complex than that. The RFC does /not/ call for closing
* down a BGP session when you change your route filters. Cisco's have to do
* this, but its not part of the RFC. So, if I, for the sake of argument,
* added a new filter /after/ I made an announcement to someone I would have to
* somewhere keep track of the fact that I made the announcement. It seems to
* me that this could get to be a bit memory intensive (keeping track of the
* state of every announcement made to every peer).