Re: 2NIC's on same network, possible?

[Justin Pryzby <justinpryzby () users sf net>]

a.b.c.d/e is a "new" notation ("CIDR") used to identify a netblock.  It
identifies a network beginning at a.b.c.d where e bytes are the network
portion.  There's an RFC that covers this in depth, but the old-style
A,B,C networks are /8, /16, /24 respectively.  A slight
overapproximation of the maximum number of hosts on a /e network is
2**(31-e).  An IP address is 32 bits, e of which identify the network.
So, 32-e of them identify the host.  There are 2**n possible ways to set
n bits (and the maximum value of n bits is 2**(n-1)).

Probably the other post was right and your friend has used a netmask
appropriate for a /e network.

Justin

On Tue, Jul 29, 2003 at 08:25:03PM +0000, chris halverson wrote:
> I am not sure what you are asking when you refer to the 2**8 - 1 addresses. 
> Can you clarify?
>
>
>
> > From: Justin Pryzby <justinpryzby () users sf net>
> > To: Vineet Mehta <vineet () linux com kw>,security-basics () securityfocus com
> > Subject: Re: 2NIC's on same network, possible?
> > Date: Mon, 28 Jul 2003 17:08:37 -0700
> >
> > That should definitely be possible, though I don't know how it will
> > decide which NIC to use for what. What do you mean '192.168.0.6/24'? A
> > NIC has an address, and that notation represents 2**8 - 1 addresses.
> > Justin
> >
> > On Tue, Jul 29, 2003 at 03:04:04AM +0000, Vineet Mehta wrote:
> > > Hi all,
> > >
> > > My collegue has a Linux machine which has 2 NIC's on it. What he did was
> > > assign the IP's 192.168.0.6/24 and 192.168.0.7/24 to the NIC's. And he
> > > was trying to ping the network but was getting errors (i dont know the
> > > errors).
> >
> > ---------------------------------------------------------------------------
> > ----------------------------------------------------------------------------
>
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