using 6to4 on two different IPv4 addresses (alias on stf0 or stf1?)

[Lapo Luchini]

I'm renumbering a server of mine in order to ease migration and am
setting most its services to listen to both the "old" and the "new" IPv4
address.
I have a little more problems with the 6to4-serviced IPv6 address:
adding an alias to stf0 doesn't seem to work, probably because the
internal sanity checks use only the first address and don't know about
the alias I added (thus this could probably be solved closing
kern/123858 but I didn't yet try that); I then tried (unsuccesfully) to
have two different 6to4 interfaces, which should IMHO work:

% sudo ifconfig stf1 create
ifconfig: SIOCIFCREATE: Invalid argument

I guess the kernel is hardwired to support only one stf interface?
BTW: that server is a 6-STABLE.

"man stf" states:
  Each stf interface is created at runtime using interface cloning.
  This is most easily done with the ifconfig(8) create command or
  using the cloned_interfaces variable in rc.conf(5).

-- 
Lapo Luchini - http://lapo.it/