ipv6: static ipv6 address with dynamic network address possible?

[Lee <ler762@gmail.com>]

Verizon FIOS finally rolled out IPv6 in my area.  yay!  I'd like for
my Debian server to have a static IPv6 address.. same as I have for
IPv4.  But how to do that?

I have a Netgate firewall that does a dhcp6 request for a /56 from
Verizon, then the firewall delegates a /64 to each internal subnet.

I haven't been able to figure out how to assign a static address when
the network part might [will] change.. so I've got everything using
managed addresses (ie. dhcp6).  So effectively the server has a static
address, but still.. I'd rather not depend on DHCPv6

Thoughts on how2?

Thanks
Lee