RFC 1101 (rfc1101) - Page 2 of 14

DNS encoding of network names and other types

RFC 1101     DNS Encoding of Network Names and Other Types    April 1989


        autonomous system names and numbers, X.500 Relative
        Distinguished Names (RDNs) and their servers, or whatever.

   It was impossible to reconcile these two areas of concern for network
   names because of the desire to unify network number support within
   existing IP address to host name support.  The existing support is
   the IN-ADDR.ARPA section of the DNS name space.  As a result this RFC
   describes one structure for network names which builds on the
   existing support for host names, and another family of structures for
   future yellow pages (YP) functions such as conversions between TCP-
   port numbers and mnemonics.

   Both structures are described in following sections.  Each structure
   has a discussion of design issues and specific structure
   recommendations.

   We wish to avoid defining structures and methods which can work but
   do not because of indifference or errors on the part of system
   administrators when maintaining the database.  The WKS RR is an
   example.  Thus, while we favor distribution as a general method, we
   also recognize that centrally maintained tables (such as HOSTS.TXT)
   are usually more consistent though less maintainable and timely.
   Hence we recommend both specific methods for mapping network names,
   addresses, and subnets, as well as an instance of the general method
   for mapping between allocated network numbers and network names.
   (Allocation is centrally performed by the SRI Network Information
   Center, aka the NIC).

3. NETWORK NAME ISSUES AND DISCUSSION

   The issues involved in the design were the definition of network name
   syntax, the mappings to be provided, and possible support for similar
   functions at the subnet level.

3.1. Network name syntax

   The current syntax for network names, as defined by [RFC 952] is an
   alphanumeric string of up to 24 characters, which begins with an
   alpha, and may include "." and "-" except as first and last
   characters.  This is the format which was also used for host names
   before the DNS.  Upward compatibility with existing names might be a
   goal of any new scheme.

   However, the present syntax has been used to define a flat name
   space, and hence would prohibit the same distributed name allocation
   method used for host names.  There is some sentiment for allowing the
   NIC to continue to allocate and regulate network names, much as it
   allocates numbers, but the majority opinion favors local control of



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