My current firewall stopped working, so I took my old and outdated APU2 firewall out of retirement. Here are the steps to get it back to work.

1. My old APU2 has only 3 NICs. I plugged in a USB2 to RJ45 NIC which now provides the 4^th NIC.
2. Since the Endian Firewall (EFW) versions are different I could not utilitze a current backup
3. I connected the APU2 with a USB to serial cable to my computer, opened PuTTY and booted the device
   • Grub will boot with Baud rate 115200, set PuTTY accordingly
   • Once EFW is running change PuTTY to Baud rate 38400
4. Login via Shell and run netwizard. You will see which interface the board listens to (green), either use that one or change the interface settings.
5. Connect your PC with static interface in the same subnet to the green interface of APU2
6. Download and install the Pale Moon browser. This is the only browser which allows to connect to TLS 1.0 and TLS 1.1, Chrome and all others block access to those protocols due to security risks.
7. Note that EFW version 3.0 was the last 32 Bit version, and APU2 has a 32 Bit CPU. EFW 3.0 goes back to the beginning of 2014. It is recommendable to use this version of EFW as a fall back only until you have built or bought a replacement for your broken firewall.
8. Connect to the EFW web interface with Pale Moon and complete the setup.
9. The SSD from my broken firewall is still accessible, so I copied all dnsmasq config files over to my APU2 which allowed a quick setup of the DHCP server.