Posts Tagged ‘linux’


DHCP servers

18 April 2007 – 21:27 CST

So I’m trying to figure something out here that really has me confused. I set up Ubuntu Edgy (server edition) and installed dhcp3-server. I’ve run DHCP servers in the past and have run linux for years, no big deal.

However, something isn’t right here. An ethernet interface is configured to be static according to /etc/network/interfaces

auto lo eth1

# The loopback network interface
iface lo inet loopback

# Intranet interface
iface eth1 inet static
hwaddress ether 00:xx:xx:xx:xx:xx
address         192.168.1.2
netmask         255.255.255.0
broadcast       192.168.1.255
network         192.168.1.0
gateway         192.168.1.1

Except, that when the interface goes down for a few minutes (ie I unplug the ethernet cable), the interface comes back up looking for an address from a DHCP server – which it finds, from itself. I’ve cleared /var/lib/dhcpd/dhcpd.leases, did a networking start/stop, rebooted, and still cannot for the life of me figure out why the system is deciding that “static” means “DHCP”.

eth0:1

31 May 2006 – 18:26 CST

Well, remember kids – taking down the physical ethernet interface with

# ifdown eth0

will also take the virtual interfaces such as eth0:1 down with it. And if you don’t have any other network enabled interfaces available – you’ve just taken your server offline 🙂