Setting up a Linux GW VI: Configuring a console friendly router and setting up static DHCP IPs

We have so far setup a device capable of working as a router for a medium sized LAN, providing NAT, DHCP and DNS services. This is great if you have a dedicated network admin, but you may prefer something easier for casual console users. We’ll see how to “refactor” your server configuration now to make it more console friendly.

Moving DHCP config files

Since I want to keep everything together for easy administration, I will move the configuration files for DHCP to /home/router/dhcp. Changing the dhcpd.conf file itself is easy, just move the subnets declarations and add this line:

include "/home/router/dhcp/subnets.conf";
include "/home/router/dhcp/static_hosts.conf";

Like we did before with bind, we need to configure apparmor. vim /etc/apparmor.d/usr.sbin.dhcpd and add this two lines:

/home/router/dhcp/ rw,
/home/router/dhcp/** rw,

Restart apparmor service, then restart dhcpd. Everything should work just fine.

Setting up static IPs

Remember the static_hosts file we created before? We can use that to define a static IP. Add the following to set a static IP host:

host HostName {
	hardware ethernet 00:00:00:00:00:00

After that, just restart the DHCP service and renew your client’s IP. Done, it’s static now!

Wait a minute: how do you find the MAC for your host? I’m to lazy to copy and type it, so I did the following:

cd /home/router/dhcp
ln -s /var/lib/dhcp leases

Then you can check the hardware address in the leases/dhcpd.leases file. I created a symlink to keep this directory at hand, since it gives you a status of the current leases.


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