underscore forbidden in subdomains ?

koudou

Verified User
Joined
Oct 13, 2003
Messages
54
why underscore is forbidden in subdomains ?

I haven't found any reason to forbid this !
Is it possible to change the test in DA to allow it ?


Michel Lo
 
The same reason you cant have an underscore on a main domain.

Chris
 
He is not being ironic, that domains is technically wrong. It is not acceptable to any standard and just because your browser supports it that does not mean that everyones does especially in todays focus on standards!

Try to ping and note it does not work. You want to know EXACTLY why? Read this RFC 952 and RFC 1123.
 
The ping works perfectly :

==================
PING la_guerre_d_espagne.crealinks.net (209.15.98.76): 56 data bytes
64 bytes from 209.15.98.76: icmp_seq=0 ttl=235 time=205.355 ms
[...]
64 bytes from 209.15.98.76: icmp_seq=9 ttl=235 time=168.575 ms

--- la_guerre_d_espagne.crealinks.net ping statistics ---
10 packets transmitted, 10 packets received, 0% packet loss
round-trip min/avg/max = 164.164/171.758/205.355 ms
==================

Beside that, you are confusing the transportation information on the net driven by RFCs and what a server does. And a server is NOT driven by RFC, it just has to comply with interface on the net.

For instance, if you want to have an email like
john%smith%senior.mydomain.com and not
[email protected] you are perfectly authorized by RFC to do so. (see RFC 819). Of course, this is not an easy way, because you have to rewrite the sofware on the server at mydomain.com , but it is perfectly "legal".

About the naming convention for subdomains, the RFC says that the convention for naming third level and over (ie subdomains and sub subdomains) are given by the higher level. In other terms, it is the responsability of domain owner to give the rules for subdomains.
(i'm not sepaking about IDNA, but only use of USASCII)

Michel Lo
 
Hello,

Valid or not, I fiind it funny that my copy of IE *crashed* when clicking that link :D

Anyway, most software doesn't care how a name is setup... it's all just plain ascii text to it, so there is no reason things like dns won't work with the underscore domain name.. It's just the one piece of software that isn't designed to handle it that they are looking out for (For example, the wonderfully programmed Internet Explorer *cough*) :)

John
 
hummm, yes, I think that the page itself has strange things.

When I try to open it with Mozilla, the image stays on different tags (pages) !!!

Probably something about strange javascript coding.

But the question was not there : Direct Admin says "not a valid name" when you try to create a subdomain name with an underscore in it.

Is there a chance to have this modified ?


Michel Lo
 
Just wondering what do you get here? http://www.dnsreport.com/ ;)

RFC 819 was just a memo, a theory that someone had in late 70's. It was writen to aid the transition from the ARPA Internet and covers internetwork applications and hierarcial names conventions. Your right that in 819 they discuss naming at the administration level. It was never a official specification. RFC 952 DID become the official speicifaction.

Why can't we support it? Stright from the horses mouth...

Hostnames can contain letters, numbers, and hyphens, and may not start with a hyphen. Underscore (_) is not a valid character in a hostname. While there are some DNS server software packages available that allow underscore within published host names, most do not. Using a domain or host name with an underscore will cause most name servers on the Internet to stop recognizing the related host/IP address.

I think if you want IDNA to be supported you will need to upgrade to BIND 9.
 
Hello,

Sorry for the change, but after doing some investigating and getting a few emails from clients, it wouldn't be wise to allow the underscore. Sorry for the flip/flop, but I've got more info now, and not allowing it is the correct solution, no matter how much fun underscores are ;).

John
 
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