On Wed, 10 Feb 2010 09:12:11 +1100, Mark Andrews said:
In message <alpine.DEB.1.10.1002091548170.25663@red.crap.retrofitta.se>, Thomas Habets writes:
On Fri, 5 Feb 2010, Mark Andrews wrote:
And now for the trick question. Is ::ffff:077.077.077.077 a legal mapped address and if it, does it match 077.077.077.077?
Forget IPv6. The first question is does 077.077.077.077 match 077.077.077.077 in IPv4?
I think you meant "does 077.077.077.077 match 77.77.77.77 in IPv4".
No, he had it right, because...
The answer is a long one full of different answers depending on who's doing the parsing (gethostbyname(), inet_aton(), inet_net_pton(), etc..) and on what OS. And also on many bugs.
Indeed. It's a minefield out there for application developers that want consistancy. Even when you develop your own some OS vendor will go and stuff it up on you.
There's no guarantee that 2 different binaries on the same box will resolve 077.077.077.077 to the same 32-bit sequence, so it's in fact possible that it's not even equal to itself, much less 77.77.77.77.