Network subnet question

[Jeff Vian]

On Tue, 2005-07-26 at 07:31 -0500, Jeff Vian wrote:
> On Tue, 2005-07-26 at 14:15 +0200, Andy Pieters wrote:
> > Hi All
> > 
> > I have a question.
> > 
> > Is 192.168.0.1 and 192.168.1.1 on the same subnet?
> > 
> > I ask because someone is having a headless server that we are supposed to 
> > connect to on 192.168.1.1 but it isn't replying and we are on 192.168.0.3
> > 
> > Thanks in advance
> > 
> 
> Technically, since 192.168.0.0 is the class B network that contains
> both, yes.
> 
> However, that depends upon your netmask.  Many use subnets of the
> 192.168 range with a class C netmask, and if you do that then your 2
> addresses are NOT in the same subnet.
> 

I know it is bad taste to reply to my own message, but RFC 1918 which
defines the private network spaces does identify the 192.168.0.0 network
as a class B network, or more specifically 
 "a set of 256 contiguous class C network numbers".  Thus with common
usage, the two networks 192.168.1.0 and 192.168.0.0 are distinct and
separate.  

As has already been noted though, any netmask from 255.255.0.0 through
255.255.255.0 is routinely used and the netmask you chose determines
whether they are in a single subnet or in separate subnets.