Ubuntu 18.04: Install isc-dhcp-server for DHCP server

This article will describe installing isc-dhcp-server and running DHCP server.

1 Install isc-dhcp-server

Install isc-dhcp-server with apt.

$ sudo apt install -y isc-dhcp-server

2 /etc/default/isc-dhcp-server

Add configuration for DHCPD. INTERFACES is a network interface name which is connected to a network which you try to provided DHCP.

$ sudo sed -e 's/^#DHCPD_CONF=/DHCPD_CONF=/g' \
     -e 's/^#DHCPD_PID=/DHCPD_PID=/g' \
     -e "s/INTERFACES=\"\"/INTERFACES=\"${INTERFACES}\"/g" \
     -i /etc/default/isc-dhcp-server

3 /etc/dhcp/dhcpd.conf

Define domain name, DHCP server IP address and gateway IP address. Mapping MAC address 52:54:00:5e:7a:a4 to IP address

$ cat /etc/dhcp/dhcpd.conf
subnet netmask {
  option domain-name "hiroom2.com";
  option domain-name-servers;
  option routers;

host dhcp-client {
  hardware ethernet 52:54:00:5e:7a:a4;
  option host-name "dhcp-client.hiroom2.com";

4 Run isc-dhcp-server

Run isc-dhpc-server with systemd.

$ sudo systemctl enable isc-dhcp-server
$ sudo systemctl restart isc-dhcp-server

5 Execution result

Run the following command on client machine.

IP address is provided.

$ ip a s
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN
group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: ens3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel
state UP group default qlen 1000
    link/ether 52:54:00:5e:7a:a4 brd ff:ff:ff:ff:ff:ff
    inet brd scope global dynamic
noprefixroute ens3
       valid_lft 42938sec preferred_lft 42938sec
    inet6 fe80::3af3:7f8b:9205:2e03/64 scope link noprefixroute
       valid_lft forever preferred_lft forever

Hostname is provided.

$ hostnamectl
   Static hostname: localhost.localdomain
Transient hostname: dhcp-client.hiroom2.com
         Icon name: computer-vm
           Chassis: vm
        Machine ID: 0a96af67dc5347faae90e4c4d1081c20
           Boot ID: a3ca7c01af46473ca57a8a326076ceb2
    Virtualization: kvm
  Operating System: Ubuntu 18.04 LTS
            Kernel: Linux 4.15.0-20-generic
      Architecture: x86-64

DNS server is provided.

$ systemd-resolve --status ens3
Link 2 (ens3)
      Current Scopes: DNS
       LLMNR setting: yes
MulticastDNS setting: no
      DNSSEC setting: no
    DNSSEC supported: no
         DNS Servers:
          DNS Domain: hiroom2.com