On Thu, 22 Aug 1996 10:27:43 CDT Chris Barnes said:
>I have a user that is complaining because LSMPT won't accept his node
>name.  It's in the form:   blah_blah.node.domain
>
>Is the "_" an illegal character?  If so, does anyone have the RFC
>reference I can give him (he'll want proof).
  Here are the relevant sections of RFC's describing host names:
RFC 952
 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
    name. No distinction is made between upper and lower case.  The first
    character must be an alpha character.  The last character must not be
    a minus sign or period.  A host which serves as a GATEWAY should have
    "-GATEWAY" or "-GW" as part of its name.  Hosts which do not serve as
    Internet gateways should not use "-GATEWAY" and "-GW" as part of
    their names. A host which is a TAC should have "-TAC" as the last
    part of its host name, if it is a DoD host.  Single character names
    or nicknames are not allowed.
 
RFC 1123
    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.
 
       Host software MUST handle host names of up to 63 characters and
       SHOULD handle host names of up to 255 characters.
 
 
In short, "_" is an invalid character in a host name.
Regards,
John Hammond