A note on callsigns, addresses and things before we start
Some AX.25 implementations such as NOS and BPQ will allow you to configure the same callsign/ssid on each AX.25 and NET/ROM port. For somewhat complicated technical reasons Linux does not allow this. This isn't as big a problem in practice as it might seem.
This means that there are things you should be aware of and take into consideration when doing your configurations.
- Each AX.25 and NET/ROM port must be configured with a unique callsign/ssid.
- TCP/IP will use the callsign/ssid of the AX.25 port it is being transmitted or received by, ie the one you configured for the AX.25 interface in point 1.
- NET/ROM will use the callsign/ssid specified for it in its configuration file, but this callsign is only used when your NET/ROM is speaking to another NET/ROM, this is not the callsign/ssid that AX.25 users who wish to use your NET/ROM `node' will use. More on this later.
- ROSE will, by default, use the callsign/ssid of the AX.25 port, unless the ROSE callsign has been specifically set using the `rsparms' command. If you set a callsign/ssid using the `rsparms' command then ROSE will use this callsign/ssid on all ports.
- Other programs, such as the ax25d program can listen using any callsign/ssid that they wish and these may be duplicated across different ports.
- If you are careful with routing you can configure the same IP address on all ports if you wish.