[DNS] Looking up europe.battle.net...
[DNS] Canonical: europe.battle.net Numerical: 213.248.106.65
[DNS] Canonical: host-66.battle.net Numerical: 213.248.106.66
[DNS] Canonical: host-67.battle.net Numerical: 213.248.106.67
[DNS] Canonical: host-68.battle.net Numerical: 213.248.106.68
[DNS] Canonical: host-200.battle.net Numerical: 213.248.106.200
[DNS] Canonical: host-201.battle.net Numerical: 213.248.106.201
[DNS] Canonical: host-202.battle.net Numerical: 213.248.106.202
[DNS] Canonical: host-204.battle.net Numerical: 213.248.106.204
Europe is the only realm that has every one of its IPs mapped to a hostname, at least according to a DNS lookup on europe.battle.net. For comparison..
[DNS] Looking up uswest.battle.net...
[DNS] Canonical: uswest.battle.net Numerical: 63.241.83.110
[DNS] Numerical: 63.241.83.111
[DNS] Numerical: 63.241.83.112
[DNS] Numerical: 63.241.83.7
[DNS] Numerical: 63.241.83.8
[DNS] Numerical: 63.241.83.9
[DNS] Numerical: 63.241.83.11
[DNS] Numerical: 63.241.83.12
[DNS] Numerical: 63.241.83.13
[DNS] Numerical: 63.241.83.107
[DNS] Numerical: 63.241.83.108
[DNS] Numerical: 63.241.83.109