[lug] IP subnetting, Firewalls, and RAID

[Andrew Diederich]

On Sat, Dec 11, 1999 at 10:40:16AM -0700, Michael J. Pedersen wrote:
> On Fri, Dec 10, 1999 at 11:21:50PM -0700, Andrew Diederich wrote:
> > IP subnetting:
> > he wants to set up a class B on a 10.x.x.x network, obviously
> internal.
> > He was thinking of using 10.1.x.x for servers, 10.2.x.x for
> developers, etc.
> > I think that he'd need routers for that, but if he shifted right one
> > in the dotted-quad he'd be OK?  So, 10.0.1.x for servers, 10.0.2.x for
> > developers, with a 255.255.0.0 netmask?  
> 
> Well, you have a couple of options, and they're decided for you by the
> subnet
> mask.  You can use the 10.x.x.x, but if you don't want to configure a
> router
> somewhere along the way, you'll have to use a subnet mask of 255.0.0.0,
> which
> will effectively make one large network.  Not the best solution.
> 
> On the other hand, using a subnet mask of 255.255.0.0, you just need to
> configure a linux box somewhere to be a router, which is actually pretty
> easy.
> Simply configure a linux box with three network cards, like so:
> 
> ifconfig eth0 internet-settings-including-netmask-address-etc
> ifconfig eth1 10.1.0.1 netmask 255.255.0.0 broadcast 10.1.255.255
> route add -net 10.1.0.0 netmask 255.255.0.0 dev eth1
> ifconfig eth2 10.2.0.1 netmask 255.255.0.0 broadcast 10.2.255.255
> route add -net 10.2.0.1 netmask 255.255.0.0 dev eth2
[snip]

Hmm.  I was pretty sure I could use IPs in the class A 10. space and just
use a different subnet mask.  I've used a combination of
10.1.x.x and 10.2.x.x before, a class C mask, with a router between, 
and it worked pretty well.  Since my friend figures he needs more
than a class C (I think) it was my understanding that I could just carve
a class B out of the 10. space and call it good without any additional
routers.  Are you sure I can't have a 10.0.x.x network and a 255.255.0.0 
mask?

[other non-IP bits snipped]

> 
> -- 
> Michael J. Pedersen
> WhoDP: whodp://earth.activerse.com/pedersen
> Check out Ding! at http://www.activerse.com


--
Andrew Diederich
andrew at netdelivery.com