[comp.dcom.sys.cisco] names with _ in it

oberman@rogue.llnl.gov (01/12/91)

In article <1991Jan11.094535@ambiorix.cs.kuleuven.ac.be>, stephan@cs.kuleuven.ac.be (Stephan Biesbroeck) writes:
> We have some names at our campus that has an _ in it (like n_kulcs).
> Our cisco CGS (running 8.1(19)) don't accept that kind of names
> (i.e. it does not ask to the name server to resolve that name. ). 
> All the other names gives no problem. All the other resolvers have no
> problem with those names. Is this a bug ?? Or a feature :-(
> I would hate to change all those names.

 From RFC1123 (Requirements for Internet Hosts -- Application and Support):

   2.1  Host Names and Numbers

      The syntax of a legal Internet host name was specified in RFC-952
      [DNS:4].  One aspect of host name syntax is hereby changed: the
      restriction on the first character is relaxed to allow either a
      letter or a digit.  Host software MUST support this more liberal
      syntax.


 From RFC952 (DOD INTERNET HOST TABLE SPECIFICATION):

 ASSUMPTIONS

   1. A "name" (Net, Host, Gateway, or Domain name) is a text string up
   to 24 characters drawn from the alphabet (A-Z), digits (0-9), minus
   sign (-), and period (.).  Note that periods are only allowed when
   they serve to delimit components of "domain style names". (See
   RFC-921, "Domain Name System Implementation Schedule", for
   background).  No blank or space characters are permitted as part of a

This means that "_" is not a legal character in names even though most
nameservers don't mind. To make sure things work you should really rename nodes
to use "-" instead of "_". It would also be nice if cisco modified the software
to accept the "_" as BIND and most other software will accept it.

I just ran into this and my thanks to Casey Leedom for the citations.

					R. Kevin Oberman
					Lawrence Livermore National Laboratory
					Internet: oberman@icdc.llnl.gov
   					(415) 422-6955

Disclaimer: Don't take this too seriously. I just like to improve my typing
and probably don't really know anything useful about anything.