Underscores in host names

Wed May 18 07:33:46 UTC 2005

Mark,

Grump.

I used to be in the 952/1123 sect, but I have since reformed and  
continue to do penance for my sins.

The "hostname is not a domain name" dodge is simply wrong.  If you  
like, I can get a signed affadavit from the author of the DNS  
specifications (assuming he's in the office tomorrow) to the effect  
that it was always his intent that domain names be composed of any 8- 
bit value.  That's the whole reason for length encoding the labels.   
RFC 2181, for all its other warts, explicitly clarified this  
particular issue.

The whole reason for check-names was because of very seriously broken  
software that would allow shell meta-characters in in-addr.arpa  
labels to do bad things.  I have come to the opinion that if such  
software still exists, then the people who run that software deserve  
what they get. Check-names was a bad idea that might have been  
justified at the time, but pretending it remains justified by  
952/1123 has got to stop sometime.

However, that rant was mostly irrelevant.  Can you point to _ANY_  
application, operating system, or anything else that has any issues  
whatsoever with an "_" of all characters?

Rgds,
-drc

On May 17, 2005, at 6:08 PM, Mark Andrews wrote:
>     RFC 952 and RFC 1123 describe what is currently legal
>     in hostnames.
>
>     Underscore is NOT a legal character in a hostname.