[Ilugc] tataindicom usb modem with mandriva2008.1
- From: knura@xxxxxxxxx (Arun Khan)
- Date: Mon Aug 25 23:04:48 2008
On Monday 25 Aug 2008, Kenneth Gonsalves wrote:
On 25-Aug-08, at 10:24 AM, Arun Khan wrote:
is this a convention or a rule?
It is a rule. In general, the IPv4_number/no_of_bits defines the
network id. The remainder bits define the "no of hosts" possible
in that network. All 0s in "host field" reserved for the network
and all 1s in "host field" reserved for broadcast.
For example a.b.c.d/24 defines a 24 bit mask, a.b.c.0 is the
network id
and a.b.c.255 is the broadcast.
so what happens if I give 192.168.1.0 as the ip for a machine on a
lan (have been doing this for 10 years or more so far)?
How many systems do you have in your network?
I conducted a small experiment with 3 physically different systems in my
LAN:
system A: ip no. 192.168.1.0 and 192.168.1.255 (original 192.168.1.68)
system B: ip no. 192.168.1.232/24
system C: ip no. 192.168.1.7 (print server)
When system A is set to 192.168.1.0 or 192.168.1.255:
On system A ping -c5 192.168.1.0 or 192.168.1.255 insists on -b
option. With -b option ping returns message from self.
On system B ping -c5 192.168.1.0 or 192.168.1.255 insists on -b
option when added returns message from system C.
On system B "ssh arunk@192.168.1.0" or "ssh arunk@192.168.1.255"
returns "host not reachable" IMO, this establishes that .0 and .255
are reserved numbers i.e. not to be assigned to any host.
system A: ip no. 192.168.1.68 (the original ip no. restored)
system B: ping -c5 192.168.1.68 works!
ssh arunk@192.168.1.68 works! I can login into my .68
machine!
If you have > 1 physical machine in your network you can do the above
and see for yourself.
Hope the above answers your question.
--
Arun Khan
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