Endereço de loopback no OS-X

Question

Wikipedia tem o que dizer sobre o endereço de loopback

Various IETF standards reserve the IPv4 address block 127/8 (from which 127.0.0.1 is most commonly used), the IPv6 address ::1, and the name localhost for this purpose.

Portanto, qualquer endereço na sub-rede 127.255.255.255 deve obedecer? No entanto, o OS-X (10.8.5) responde apenas a pings em 127.0.0.1

$ ping 127.0.0.1
PING 127.0.0.1 (127.0.0.1): 56 data bytes
64 bytes from 127.0.0.1: icmp_seq=0 ttl=64 time=0.050 ms
64 bytes from 127.0.0.1: icmp_seq=1 ttl=64 time=0.077 ms
^C

$ ping 127.1.2.3
PING 127.1.2.3 (127.1.2.3): 56 data bytes
Request timeout for icmp_seq 0
Request timeout for icmp_seq 1
^C

O Linux (uma antiga VM Ubuntu 10.04) responde a partir do endereço fornecido

$ ping 127.1.2.3
PING 127.1.2.3 (127.1.2.3) 56(84) bytes of data.
64 bytes from 127.1.2.3: icmp_seq=1 ttl=64 time=0.088 ms
64 bytes from 127.1.2.3: icmp_seq=2 ttl=64 time=0.022 ms
^C

Enquanto o Windows (XP) responde sempre de 127.0.0.1

C:\>ping 127.1.2.3

Pinging 127.1.2.3 with 32 bytes of data:

Reply from 127.0.0.1: bytes=32 time<1ms TTL=128
Reply from 127.0.0.1: bytes=32 time<1ms TTL=128

O OS-X não está em conformidade com os padrões aqui? E o XP?