This article was written a long time ago. It should be improved to match the tone of the rest of the website. Update this article with recent work done on secondary IP.
Traditionally most enterprise environments used static IP. This is changing somewhat due to virtualization and the concept of stateless applications. But it's not quite there yet.
For your home server environment you might want to use Bonjour name resolution instead and just go by hostname.
Assuming your existing install is picking up DHCP correctly and your network is working fine. If you are learning using virtual machine softare like VMWare, ensure your guest OS network is set to use Bridged Networking. This will not work with sharing the network.
If possible, it is advised to be sure you can reach your machine via a console mechanism or experiment on a test machine first.
This will list your network cards. Usually you will see eth0 as being the network card enabled. Record the highlighted entries,
Now I don't know how to get the rest on Ubuntu quite yet (now I do), so I go to a Windows machine on the same network and type,
Again, record the Default Gateway, line item 9, for the Ethernet adapter Local Area Connection,
Do a ping to verify that no other device is using the IP address. In this example we want to use 192.168.0.50,
Next on your Ubuntu machine,
The file will look like this,
The area where you file might be different is eth0 may be ens3 or something similar. This changes depending on your version of Ubuntu and setup.
We modify the file and choose 192.168.0.50. Note that this ip address would never be assigned by my router as I modified the router's dhcp address range from 192.168.0.2 - 192.168.0.255 to only provide DHCP between 192.168.0.100 - 192.168.0.255. My router itself is using the ip address 192.168.0.1.
If you have not already, make sure are running from the console for this step. Otherwise you will be disconnected and have to connect again with the new ip address.
Now we restart the network services,
Verify by pinging your system from another machine.
After you know things are working you may want to uninstall the dhcp package. I have read (but not experienced myself) that after a certain amount of time it will take control and you will end up with a dhcp assigned ip.
Some instructions mention you need network and broadcast, but they are automatically calculated from the address and netmask values. In fact adding the wrong ones can prevent things from working so I recommend leaving them out.
If you have more than one dns server use the format, dns-nameservers 220.127.116.11 18.104.22.168
- Explains name servers are required for static entries - https://wiki.debian.org/NetworkConfiguration#Configuring_the_interface_manually