[NETWORK]
enp1s0=192.168.127.254   # leftmost socket: connect here a moxa with factory settings
enp2s0=192.168.2.2       # connected device will get this ip via DHCP 
enp3s0=192.168.3.3       #    or must be configured static to this IP
enp4s0=dhcp              # rightmost socket is the uplink

[ROUTER]
3000=/dev/ttyUSB0       # routing 3000 to the internal serial port /dev/ttyUSB0
5900=192.168.2.33       # routing VNC (local port 5900 to port 5900 on 192.168.2.33
8080=192.168.127.254:80 # routing 8080 to port 80 of 192.168.127.254

[FRAPPY]
cfg=uniax   # the cfg file for the frappy server
port=5000   # the port for the frappy server

network configuration

The example above fits the most cases. Here a detailed description of possible settings:

fixed IP

enp2s0=192.168.3.5

Configure the IP address of the connected device to get the specified IP via DHCP or configure the device to with this static IP. The last number must be within 1..254, the APU port itself will get 1 (or 2, if the specified IP is 1).

custom network

enp3s0=192.168.3.1/24  # our ip address, the static address of the connected device must
                       # be within 1-254 and not match our own

24 means 24 bit = 3 bytes network address. A local network with static addresses. This way, the APU can get an other address than 192.168.x.1 or 192.168.x.2 or the network address size might be defined other than 24. Probably needed rarely.

uplink via DHCP

enp4s0=wan    # or enp4s0=dhcp

Uplink configured for DHCP in any network n.x.y.z with n < 192

customized uplink

enp1s0=wan,192.168.1.0/24

Add more networks to the allowed uplink range. More than one range is allowed, comma separated. Must not overlap networks specified for other ports!

disabled port

enp3s0=off             # disabled