From: Jamie C. <jca...@we...> - 2003-01-10 00:14:30
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The funny thing is, BIND 9 supports them and some people running networks with lots of Windows systems have to use them.. so Webmin does too, even though they are not technically legal. - Jamie Jason Oakley wrote: > http://www.acmebw.com/askmrdns/archive.php?category=81&question=604 > > > Just to be clear, underscore has *NEVER* been legal as a hostname > character. Never. To this day it is still not legal. > <http://www.ietf.org/rfc/rfc952.txt>RFC 952 and > <http://www.ietf.org/rfc/rfc1123.txt>RFC 1123 state the rules. Nevermind > that it is legal in NetBIOS names. Nevermind that many Unix vendors tell > you it is legal in their instructions for setting the hostname. > > Some people reject names with underscores in them at the DNS server > because there's an option for it. That option exists because of some > hoopla about root exploits in badly behaving applications that blindly > pass the results of PTR lookups to other system calls. However, DNS > servers were not designed to enforce hostname rules. Those rules should > be enforced at the client, so the default setting on servers is to allow > all characters through. That's the skinny on underscores. > > FYI, if you stick with the legal Internet *hostname* character set, > you'll never run into problems. > > > At 03:55 PM 9/01/2003 +1100, you wrote: > >> No .. but isn't _ a valid character in a DNS name? > > > Regards, > > Jason. > |