I'm not sure that I completely understand your problem.
It sounds like you're trying to affect ingress routing policy based on IPv6 prefix.
This essentially works the same as it does in IPv4 - and FYI, the general concensus for longest globally-routed prefix is /48 (meaning /49 - /128 aren't going to make it everywhere in the global IPv6 routing table)
Substitute your real IPv6 prefix with 2001:db8 and give real examples of the prefixes you're trying to announce. It would help tremendously to have some more concrete info to work on.
(so if your real IPv6 prefix were 41cf:9ac4:c000::/40 you should post it here as 2001:db8:c000::/40)
Some BGP basics to keep in mind:
- For each prefix that you wish to originate into BGP (ip4 or ip6 doesn't matter), you must have one network statement for
exactly that prefix.
- That prefix must exist as an active route in the router's ipv6 routing table (assuming that you've not disabled synchronization - which is a bad habit for eBGP routers)
Suppose you had configured network 2001:db8
:/48 in your BGP....
Suppose further that you have 2001:db8
aa00::/56 active in your routing table. This prefix would NOT be originated into BGP by your router because there is no such prefix configured.
Let's also say that there is no route in your routing table for 2001:db8
:/48 - your router would not originate this prefix even with the network statement in place because there is no active route in the routing table.
Final detail - if some other router within your own ASN (an iBGP neighbor) is actually originating some prefix, then that prefix WILL be passed to all eBGP neighbors unless blocked by a filter or if that eBGP neighbor is giving you a better path than the one in iBGP)
If you're announcing /64 prefixes - then I assume you're either adding those as networks, or else you're redistributing connected or static routes into BGP (you really should never redistribute routes into the global BGP table - you should properly originate them with network statement + reachability)
Hope some of these general-purpose thoughts about BGP help you get to the bottom of things. Otherwise, feel free to post some more specific info and the forums community should give you some insights.