Adding hint on IPv6 zones

[momorientes]

It might also be worth expanding the prefixes in the introduction by:

0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa (Unspecified)
                            f.f.ip6.arpa (Multicast)
                          8.e.f.ip6.arpa (Link-Local Scope)
                          9.e.f.ip6.arpa (Link-Local Scope)
                          a.e.f.ip6.arpa (Link-Local Scope)
                          b.e.f.ip6.arpa (Link-Local Scope)
                          c.e.f.ip6.arpa (Link-Local Scope)
                          d.e.f.ip6.arpa (Link-Local Scope)
                          e.e.f.ip6.arpa (Link-Local Scope)
                          f.e.f.ip6.arpa (Link-Local Scope)
                        0.0.c.f.ip6.arpa (Unique Locally Assigned)
                        0.0.d.f.ip6.arpa (Unique Locally Assigned)
                0.0.0.0.1.0.0.2.ip6.arpa (Teredo)