Hello Darren,
neighbor default-originate
To allow a BGP speaker (the local router) to send the default route 0.0.0.0 to a neighbor for use as a default route, use the neighbor default-originate command in address family or router configuration mode. To send no route as a default, use the no form of this command.
neighbor {ip-address | peer-group-name} default-originate [route-map map-name]
no neighbor {ip-address | peer-group-name} default-originate [route-map map-name]
see
http://www.cisco.com/en/US/docs/ios/iproute/command/reference/irp_bgp3.html#wp1013044
+
filters towards BGP sessions to other non branch neighbors
ip prefix-list only-default permit 0.0.0.0/0
route-map to-nonbranch deny 10
match ip address prefix-list only-default
route-map to-nonbranch permit 20
This should be usable also if you are using MPLS L3 VPN services
Hope to help
Giuseppe
Hope to help
Giuseppe