********************************************************************** FTSC FIDONET TECHNICAL STANDARDS COMMITTEE ********************************************************************** Publication: FRL-1019 Revision: 1 Title: IPv6 colon substitution in the nodelist. Author(s): Michiel van der Vlist Date: 28 Februari 2010 ---------------------------------------------------------------------- Contents: 1. Introduction. 2. The problem. 3. The solution. 4. The standard. ---------------------------------------------------------------------- Status of this document ----------------------- This document is a Fidonet Reference Library Document (FRL). This document preserves FSP-1025 which was withdrawn by the author in favour of FSP-1036 titled "IPv6 numbers in the nodelist". This document is released to the public domain, and may be used, copied or modified for any purpose whatever. 1. Introduction --------------- In addition to the classic modem connection over telephone lines FidoNet increasingly makes use of the InterNet for its links. This means InterNet contact information needs to be in the nodelist. Up to now, this has been in the form of IP quads and fqdn's. (Fully Qualified Domain Names). In the future the need to have IPv6 addresses in the nodelist may very well arise. There is problem however. 2. The Problem -------------- The format of an IPv6 address is: Eight hexadecimal values in the range 0-FFFF separated by a colon. One or more successive zero values may once be represented by two successive colons. F.e. 1234::6789:abcd expands to 1234:0:0:0:0:0:6789:abcd. The problem is that the colon is already in use to separate a nodelist flag from its parameter(s), that some flags may carry a variable number of parameters and that the colon is also used to separate parameters from each other. F.e. a flag carrying both an fqdn and a port number: FLAG:fido.ddutch.nl:1234 Having the same character for separating parameters as for separating individual items within a multidimensional parameter creates a parsing problem. Does 1234::6789:abcd:5678 resolve to address 1234:0:0:0:0:0:6789:abcd with a port number of 5678 or does it resolve to just an address of 1234:0:0:0:0:6789:abcd:5678 and no port number specified? 3. The Solution --------------- The solution is obvious: the colons in IPv6 are to be substituted by something else. The choice of what character to use is however less obvious. About half a dozen characters are equally suitable. This will lead to different developers making different choices. Setting an early standard will avoid that. 4. The standard --------------- Whenever an IPv6 address is to appear as a parameter in the nodelist the colons in the address shall be replaced by a hash character ( # ), hex 23. The colon separating the address from another parameter such as a port number shall remain as is. Example: 1234##6789#abcd:5678 References ---------- [FTS-5] "The distribution nodelist", Ben Baker, Rick Moore. February 1989. Obsoleted by FTS-5000. [FTS-5000] "The distribution nodelist". Colin Turner, Andreas Klein, Michael McCabe, David Hallford, Odinn Sorensen. June 1999. [FTS-5001] "Nodelist flags and userflags". Colin Turner, Andreas Klein, Michael McCabe, David Hallford, Odinn Sorensen. June 1999. [RFC1883] S. Deering, R. Hinden. Internet Protocol, version 6 (IPv6) Dec 1995 [RFC1884] S. Deering, R. Hinden. IP Version 6 Addressing Architecture. Dec 1995 Contact Data ------------ Michiel van der Vlist Fidonet: 2:280/5555 E-mail: pa0mmv at vrza dit org administrator at ftsc dot org History ------- Rev.1, 20030908: Initial Release. Principal author Michiel van der Vlist. ------ 20100228: Re-assigned from FSP-1025 to FRL-1019 **********************************************************************