Click on the Apple menu on the top menu bar and open “System Preferences”

In the system preferences window, click on “Print & Fax”

Click the “+” symbol below the list of printers

The “Add Printer” window should open. If it’s not already selected, click the “IP” tab at the top

Set the protocol as “Line Printer Daemon – LPD”

In the address field, type 172.24.126.19

Name the printer appropriately (e.g. Frank Group BW); you don’t need to fill in the “location” field

Open the “Print Using” dropdown box and choose “Select Printer Software”

Search for “LaserJet 2420,” select it, and click “OK”

Click “Add”

A window labeled “Installable Options” will appear. Check the “Duplex Unit” box, which sets double-sided printing as the default

Click “Continue”

The printer is installed and ready to use.