ethernet

a314eth.device - SANA-II driver for A314

This SANA-II driver works by copying Ethernet frames back and forth between the Amiga and a virtual ethernet interface (tap0) on the Raspberry Pi. The Pi will, when configured properly, do network address translation (NAT) and route packets from the Amiga to the Internet.

Configuring the Raspberry Pi

If the install-pi.sh script was run to setup the Raspberry Pi then the following steps have already been carried out, and no more configuration should be needed unless your network require some special configuration.

• Install pytun: sudo pip3 install python-pytun.
• Copy ethernet.py to /opt/a314/ethernet.py.
• Update /etc/opt/a314/a314d.conf with a line that starts ethernet.py on demand.
  • In order for a314d to pick up the changes in a314d.conf you'll have to restart a314d, either by sudo systemctl restart a314d or by rebooting the Pi.
• Copy pi-config/tap0 to /etc/network/interfaces.d/tap0. This file creates a tap device with ip address 192.168.2.1 when the Raspberry Pi is booted up.
• Enable ip forwarding by uncommenting the line in /etc/sysctl.conf that says net.ipv4.ip_forward=1.
• Add the lines in pi-config/rc.local to the bottom of /etc/rc.local just before exit 0. This create iptables rules that forwards packets from the tap0 interface to the wlan0 interface.
  • Please note that if the Pi is connected using wired ethernet then wlan0 should be changed to eth0.

Configuring the Amiga

This has been tested with the Roadshow and the MiamiDX TCP/IP stacks. These instructions show how to configure Roadshow and Miami for a314ethernet, they do not describe how to install either.

Common

• Copy a314eth.device to DEVS:.

Roadshow

• Copy amiga-config/A314Eth to DEVS:NetInterfaces/A314Eth.
• Copy amiga-config/routes to DEVS:Internet/routes.
• Copy amiga-config/name_resolution to DEVS:Internet/name_resolution.
  • You should change the nameserver to a DNS server that works on your network.
  • Note that there may be settings in the above two files (routes and name_resolution) that you wish to keep, so look through the changes you are about to make first.

Reboot the Amiga and with some luck you should be able to access the Internet from your Amiga.

Miami

• Create new device entry under Hardware
  • Click New and select Ethernet
  • Name it accordingly, for example a314eth
  • Type should be SANA-II driver
  • For Driver, type in, or browse to and select, DEVS:a314eth.device and click OK
• Create a new network interface in Interfaces
  • Click New and select Ethernet and Internet, click OK
  • Select the previously created a314eth and click OK
  • Set IP to static and type in 192.168.2.2
  • Set Netmask to static and type in 255.255.255.0
  • Set Gateway to static and type in 192.168.2.1
  • Click OK
• Add a nameserver in Database
  • Select DNS servers from the spinner
  • Click Add and type in the address of your DNS server and press enter (you can use for example Google's DNS server at 8.8.8.8 if unsure)
• Remember to save your settings!

Click Online and hopefully your Amiga now has internet access.

Autostarting Miami and further configuration is left to the user.

Networking Tips and Tricks

Accessing services on your Amiga from other computers on the network

The above described configuration uses a method called masquerading to create a separate network for your Amiga behind the Pi. While this has the advantage of shielding it from attacks from other computers, sometimes you may want to be able to access network services on your Amiga from other computers besides the Pi.

To facilitate that access, the firewall on the Pi needs to be configured to forward incoming traffic on specific ports on the external interface to the Amiga. The example below assumes that the Pi and Amiga have both been setup as described earlier in this document.

iptables -A PREROUTING -t nat -i wlan0 -p tcp --dport 21 -j DNAT --to 192.168.2.2:21
iptables -A FORWARD -p tcp -d 192.168.2.2 --dport 21 -j ACCEPT

By adding these lines to /etc/rc.local directly following the other /iptables/ lines, the Pi firewall will start accepting connections to port 21 (FTP) and forwarding them to port 21 on the Amiga allowing an FTP client to connect to an FTP server running on the Amiga.