How to reserve IP Address in DHCP Server

Question

I install DHCP Server with https://help.ubuntu.com/lts/serverguide/dhcp.html

but I need to make reserve IP addresses for specific machine (192.168.1.XXX) and further to assign a name to each machine (machine 1 machine 2 machine 3).

My configuration file is as follows.

default-lease-time 600;
max-lease-time 7200;

subnet 192.168.1.0 netmask 255.255.255.0 {
range 192.168.1.2 192.168.1.249;
option routers 192.168.88.250;
option domain-name-servers 192.168.1.x, 8.8.8.8;
option domain-name "mydomain.lan"; }

This is to replace fortinet service and add hostnames for each IP assigned and have control of them.

If there is any visual alternative (via web) to manage what I need, would be helpful.

Solution

In this example the DHCP server IP address reservation will use the NIC's MAC Address. You need to know the MAC address to add it to DHCP configuration file. (I will be using a dummy MAC address and IP address in the example).

To find the MAC address use ifconfig, and look for the HWaddr entry

To do so, just press Ctrl+Alt+T on your keyboard to open Terminal. When it opens, run the command(s) below:

sudo nano /etc/dhcp3/dhcpd.conf

and add the following lines:

host Accountant {
hardware ethernet 00:1F:6A:21:71:3F;
fixed-address 10.0.0.101;
}

Save file and exit.

Now the DHCP server will always assign 10.0.0.101 to the 00:1F:6A:21:71:3F MAC address.

Restart DHCP

service dhcpd restart

or

sudo /etc/init.d/dhcp3-server restart

Comments

[JHOSMAN]

So if I have it clear, in fact that it makes my Fortinet device, but want to be able to further identify the MAC address to assign its hostname

[Mitch]

Are you asking if you have to know the MAC address of all devices that you need to reserve and IP for?

[JHOSMAN]

There are many machines that I administer, it would be easier if you could put an alias or hostname to search for them and not a MAC address.

[JHOSMAN]

It's possible to my question? ** host NAMEHOST { ... }** host HSLABTEACHER01 { hardware ethernet 00:25:64:be:3f:48; fixed-address 192.168.1.3; } host ESLABTEACHER01 { hardware ethernet 00:25:64:c2:c4:d7; fixed-address 192.168.1.5; } host NOTE2 { hardware ethernet e0:cb:4e:37:2b:92; fixed-address 192.168.1.4; } host ACCOUNTANT { hardware ethernet 44:87:fc:95:de:3f; fixed-address 192.168.1.6; } host SECRETARY { hardware ethernet 00:26:2d:2e:19:c1; fixed-address 192.168.1.7; }

[Mitch]

You may want to take a look at DHCP

[Qian Chen]

Other than IP, what if I need to set mask, gw, add route, can I do all of these here? Thanks.

[Mitch]

@ElgsQianChen You sure can.

[bgStack15]

Sometimes, a pool is just not good enough. You need to narrow down a single IP address for a single client, without the ability to adjust the client (I'm looking at you, Chromecast).