zone file question

Mark_Andrews at Mark_Andrews at
Sat Jan 18 11:29:08 UTC 2003

> I have a question about the generic zones listed in RFC1912. The RFC 
> explains that two zones, and, should 
> always be set up to prevent queries of the network and broadcast 
> addresses from 'escaping' into the internet and hitting a root name server.
> My question is; if my network is a classless network, should the two 
> zones still be called as above or should they match the network and 
> broadcast addresses of my network?
> So, if my IP address space is 192.168.20/27 with a network address of 
> and a broadcast address of, should the two 
> zones be called and

	No. is still used by machines that don't know their
	address and is a valid broadcast address on
	all networks.  The purpose of those zones is to catch reverse
	lookups on those addresses. catches reverse
	lookups on 0.x.x.x and catches reverse lookups
	on 255.x.x.x.  Note these are the first (not last) octets of
	the addresses.

	However you should have a zone for the address range you are
	using.  Since you don't have a full /24 you should look at
	RFC 2317 and choose a method along with your address provider. and
	are the start and end of this address range in the
> Andrew
Mark Andrews, Internet Software Consortium
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: Mark.Andrews at

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