nanog mailing list archives
Re: Regular Expression for IPv6 addresses
From: Valdis.Kletnieks () vt edu
Date: Tue, 09 Feb 2010 17:25:28 -0500
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.
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Current thread:
- Re: Regular Expression for IPv6 addresses, (continued)
- Re: Regular Expression for IPv6 addresses Jeroen Massar (Feb 04)
- Re: Regular Expression for IPv6 addresses Mark Andrews (Feb 04)
- Re: Regular Expression for IPv6 addresses Jeroen Massar (Feb 04)
- Re: Regular Expression for IPv6 addresses Mark Andrews (Feb 04)
- Re: Regular Expression for IPv6 addresses sthaug (Feb 04)
- Re: Regular Expression for IPv6 addresses James Hess (Feb 06)
- Re: Regular Expression for IPv6 addresses Mark Andrews (Feb 06)
- Re: Regular Expression for IPv6 addresses Mark Andrews (Feb 04)
- Re: Regular Expression for IPv6 addresses isabel dias (Feb 05)
- Re: Regular Expression for IPv6 addresses Jeroen Massar (Feb 04)
- Re: Regular Expression for IPv6 addresses Thomas Habets (Feb 09)
- Re: Regular Expression for IPv6 addresses Mark Andrews (Feb 09)
- Re: Regular Expression for IPv6 addresses Valdis . Kletnieks (Feb 09)