Achieving Wired Connection Without Router

This is a procedure for connecting a laptop that does not have wireless to one that does, via a direct ethernet wired connection.

First, connect the wired ports of the two computers using a standard ethernet cable. (Once long ago you had to use crossover cables for this, but modern computers have auto-switching so no special cable is required.)

On the master system that *has* functional wireless:

Go to Edit Connections
On the Wired tab, select the connection (e.g. "Auto eth0") and click Edit
on the IPv4 Settings tab, change Method to 'Shared to other computers', and click Apply
Run 'ipconfig' and note the eth0 IP address chosen

On the slave system, that doesn't have wireless:

Go to Edit Connections
On the Wired tab select the connection (e.g. "Auto eth0") and click Edit
On the IPv4 Settings tab, change Method to Manual
Type in the master system's IP address for Gateway (E.g. 10.42.43.1)
For Netmask type in 254.0.0.0
For Address type in a number 1 greater than the Gateway (E.g. 10.42.43.2)
Click Save