How to Configure Network with static and dhcp in Linux.

A static ip is an IP address that configured for a device instead of one provided by a DHCP server,called static because it does not change or a dynamic IP address which does change.Static IP addresses is mostly used to eliminate the network traffic associated with DHCP/DNS.

A dynamic IP address is automatically assigned to each connection, or of a network like laptop or phone.A DHCP server provide IP address,called dynamic because it will be different connections to the network.

Start,Enable & Stop Network Manager

systemctl start network-manager
systemctl enable network-manager
systemctl stop network-manager

Check supported interface.

ifconfig -a

Check status of the interface.

ifconfig eth0

Setup DHCP using CLI

echo “iface eth0 inet dhcp” >>/etc/network/interfaces

To bring up network Interface.

ifconfig eth0 up
or
ifup eth0

To setup static IP, subnet mask, broadcast address.

ifconfig eth0 ip-address
ifconfig eth0 netmask subnet-mask
ifconfig eth0 broadcast broadcast-ip-address

Check the IP address,netmask & broadcast ip address.

ifconfig eth0

Here is the command output.

We need to setup Gateway address for the interface.Add default Gateway route to eth0.

route add default gw gateway-ip-address eth0

Check the configure

route -n

Here is the command output.

Another way to setup static ip in DHCP network.

echo -e “iface eth0 inet dhcp\n address ip-address\n netmask subnet-mask\n gateway
gateway-ip-adress″>>/etc/network/interfaces 

If network interface is not up so we needs to bring up.

ifconfig eth0 up
or
ifup eth0

Now we can using ping command to check network connection.

ping ip-address

Setup nameserver / DNS.If we are getting a DNS error than we needs to assign DNS servers manually.

echo “nameserver server-dns-ip\n nameserver another-server-dns-ip″ >>/etc/resolv.conf

example: echo “nameserver 8.8.8.8\n nameserver 8.8.4.4″ >>/etc/resolv.conf