Two elementary questions on LANs

[Ed Greshko]

On 06/16/2011 07:00 PM, Timothy Murphy wrote:
> 1) I was trying to change a LAN on my home-system
> from 192.168.1.0 to 192.168.2.0
> but I found it surprisingly difficult for example
> to change my laptop from 192.168.1.7 to 192.168.2.7 .
> I made the change in /etc/sysconfig/network-scripts/ifcfg-eth1
> and deleted all the files in /var/lib/dhclient with the old address.
> But when I re-booted the old address came up,
> as given by ifconfig and route (or ip route).
> I was running NetworkManager, but I didn't see
> the IP address specified in /etc/NetworkManager .
> I may say the laptop was WiFi connected to a LinkSys router running dhcp,
> but the Local IP Address in this had been changed to 192.168.2.1 .
>
> Who decides the IP address of a device?

In your /etc/sysconfig/network-scripts/ifcfg-eth1  What is the BOOTPROTO ?

If it is dhcp then the answer to your question is your dhcp "server". 

The files in /var/lib/dhclient contain the information of you lease that
is served up by the dhcp server.

FWIW, that file would also contain dhcp-server-identifier which would
tell you what system issued the lease.

Ed