Setting Router dan DHCP Server pada Ubuntu 12.04 Linux

Asumsi
eth0: IP 192.168.2.101 (terhubung ke Internet dengan NameServer: 192.168.2.1)
eth1: IP 192.168.1.1 (Terhubung ke LAN, IP LAN Client 192.168.1.2-192.168.1.254)

1. Konfigurasi IP
# gedit /etc/network/interfaces
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auto lo
iface lo inet loopback
auto eth0
iface eth0 inet static
address 192.168.2.101
netmask 255.255.255.0
gateway 192.168.2.1
network 192.168.2.0
broadcast 192.168.2.255
dns-nameservers 192.168.2.1
dns-search belajarserver.ok
auto eth1
iface eth1 inet static
address 192.168.1.1
netmask 255.255.255.0
network 192.168.1.0
broadcast 192.168.1.255
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# /etc/init.d/networking restart
2. Konfigurasi Routing (iptables)
# gedit /etc/sysctl.conf
Cari kata berikut, hilangkan tanda pagar didepannya
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net.ipv4.ip_forward=1
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# sudo sysctl -w net.ipv4.ip_forward=1
# sudo /sbin/iptables -P FORWARD ACCEPT
# sudo /sbin/iptables –table nat -A POSTROUTING -o eth0 -j MASQUERADE
Taruh di rc.local, agar konfigurasi tidak hilang:
# gedit /etc/rc.local
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sudo /sbin/iptables -P FORWARD ACCEPT
sudo /sbin/iptables –table nat -A POSTROUTING -o eth0 -j MASQUERADE
exit 0
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# sudo apt-get install isc-dhcp-server
# sudo gedit /etc/dhcp/dhcpd.conf
Cari kata
A slightly different configuration for an internal subnet
Buat baris berikut di bawahnya
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subnet 192.168.1.0 netmask 255.255.255.0 {
range 192.168.1.2 192.168.1.250;
option domain-name-servers 192.168.2.1;
option domain-name “bkpgorontalo.org”;
option routers 192.168.1.1;
option broadcast-address 192.168.1.254;
default-lease-time 3600;
max-lease-time 7200;
}
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# sudo gedit /etc/default/isc-dhcp-server
Cari kata
INTERFACES=”"
Ubah menjadi
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INTERFACES=”eth1″
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# sudo service isc-dhcp-server stop
# sudo service isc-dhcp-server start
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Semoga bermanfaat  :)