RFC 2224 (rfc2224) - Page 2 of 11

NFS URL Scheme

RFC 2224                     NFS URL Scheme                 October 1997


      10.   BNF for NFS URL Scheme . . . . . . . . . . . . . . . . .  9
      11.   Acknowledgements . . . . . . . . . . . . . . . . . . . . 10
      12.   Author's Address . . . . . . . . . . . . . . . . . . . . 10
      13.   Full Copyright Statement . . . . . . . . . . . . . . . . 11

1. URL Syntax

   An NFS URL is based on the Common Internet Scheme Syntax described in
   section 3.1 of RFC 1738.  It has the general form:

        nfs://:

   The ":" part is optional.  If omitted then port 2049 is
   assumed.  The  is also optional.

   The  is a hierarchical directory path of the form
   ////.../. The  must
   consist only of characters within the US-ASCII character set.  Within
   a  or  component the character "/" is reserved and
   must be encoded as described in Section 2.2 of RFC 1738.  If  is omitted or consists solely of "/", it must default to the
   path ".".

2. URL Evaluation

   A client must evaluate an NFS URL by a method known as WebNFS
   [RFC 2054, RFC 2055]. This method provides easy passage through
   firewalls and proxy servers, as well as using a minimum number of
   messages.  The WebNFS method is defined for NFS versions 2 and 3. It
   assumes that the server registers on TCP or UDP port 2049 and
   supports the public filehandle and multi-component lookup semantics
   as described in the following sections.

3. Server Connection

   The client must first attempt to create a TCP connection to 
   using the  specified.  If : is omitted, then port 2049
   will be used.  If the server refuses the TCP connection, then the
   client will use UDP.

4. NFS Version

   The client must first attempt to use NFS version 3.  If the server
   returns an RPC PROG_MISMATCH error then the client must assume that
   NFS version 3 is not supported, and retry the operation with an NFS
   version 2 public filehandle.





Callaghan                    Informational