Van privat cimtartomany:
fc00::/7 are the unique-local addresses [RFC4193]. Addresses within
this block should not appear by default on the public Internet.
Procedures for advertising these addresses are further described in
NAT meg innentol csak feature.
Az hogy kinek mikor mekkora prefixet adnak az nem hasrautes, a kovetkezo semat kene mindenkinek kovetni es akkor jut is marad is: http://www.ietf.org/rfc/rfc2374.txt