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Wikipedia has this to say about the loopback address

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

So any address in the subnet should comply? However OS-X (10.8.5) only responds to pings on

$ ping
PING ( 56 data bytes
64 bytes from icmp_seq=0 ttl=64 time=0.050 ms
64 bytes from icmp_seq=1 ttl=64 time=0.077 ms

$ ping
PING ( 56 data bytes
Request timeout for icmp_seq 0
Request timeout for icmp_seq 1

Linux (an old Ubuntu 10.04 VM) responds from the supplied address

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

While Windows (XP) responds always from


Pinging with 32 bytes of data:

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

Is OS-X not conforming to the standards here? What about XP?

share|improve this question
Seems this is related and indicates that OS-X is not conforming - so what about XP? – Peter Gibson Feb 13 '14 at 23:01

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