On Thu, 18 Aug 2005, Steven Wayne wrote:
> > I didn't know mx records couldn't be ip addresses....
RFC 1034:
"The MX RRs have an RDATA section which consists of a 16 bit number
followed by a domain name."
RFC 974:
"For the purposes of message routing, the system stores RRs known as
MX RRs. Each MX matches a domain name with two pieces of data, a
preference value (an unsigned 16-bit integer), and the name of a
host."
Note that, as a result of pressure long ago from a certain multinational
company whose name starts with the digit 3, components of domain names
are permitted start with digits. Thus, an IPv4 address is a
syntactically valid domain name. A nameserver cannot therefore object to
being told to load a record such as
xxx MX 1 1.2.3.4
because, syntactically, "1.2.3.4" *could* be a domain name. Sigh.
--
Philip Hazel University of Cambridge Computing Service,
ph10@??? Cambridge, England. Phone: +44 1223 334714.
Get the Exim 4 book: http://www.uit.co.uk/exim-book
