command line example cause it is so quick and simple

On computer A

    sudo ip ad add dev eth0

On computer B

    sudo ip ad add dev eth0

To test from A to B


To test from B to A


Provided that a cable is connecting the two computers and the network interface on both of them is enabled and called eth0 this should work. The rest of this post is to help trouble shoot if there are problems.

10.0.0.xx is the ip address of the computers. /24 tells the computers that the last 8 bits of the 32 bit ip address can change. It is similar to saying netmask This set ups the routes that the computer / network has available to it.

you should see some thing similar to this using

    ip route dev eth0 proto kernel scope link src

If you don't see some thing like above in the route table but see some thing like this when you use ip ad. You need add the address again using /24 subnet syntax.

    ip ad
    inet scope global eth0

Notice the /32 which effectively is saying that is the only computer that exists on a network of one computer. Which is its self. Net mask Hence no routes and the network does not work.

To find out which network interfaces you have and which are working

# ip ad
1: lo:  mtu 16436 qdisc noqueue 
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet scope host lo
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: eth0:  mtu 1500 qdisc pfifo_fast qlen 1000
    link/ether 46:fd:51:f9:f5:2e brd ff:ff:ff:ff:ff:ff
    inet brd scope global eth0
    inet scope global eth0
    inet scope global eth0
    inet6 fe80::44fd:51ff:fef9:f52e/64 scope link 
       valid_lft forever preferred_lft forever
3: eth1:  mtu 1500 qdisc noop qlen 1000
    link/ether 72:3f:92:eb:a4:cc brd ff:ff:ff:ff:ff:ff

If you need to delete an ip address cause you made a mistake

    ip ad del dev eth0 ip ad del dev eth0

This will remove the routes as well as the ip address.