• It is assumed that Linux kernel you have is AX.25 ready if it is not you need to:
  • Build a new kernel with AX.25 enabled OR
  • Install the AX.25 kernel module

Below is a collection of links of good tutorials for setting up AX.25. I recommend you read them as what follows in this wiki is just a summary of what is needed to get AX.25 configured to run paclink-unix.

• Linux AX.25 Configuration - by John Ackermann
• Also check out Linux Amateur Radio AX.25 HOWTO - by Jeff Tranter, VE3ICH
• Charles Schumann K4GBB has very good notes on setting up AX.25 & an RMS Gateway on the Raspberry PI here

• Install libax25, apps & tools from linux-ax25.org Main page
  • Download the 3 files under 'Latest Versions' from right hand side
  • There are other versions of these packages that have been modified or patched to be 'better' but let's get this going with the vanilla sanctioned packages first.
  • The packages available from the Debian/Ubuntu repositories tend to be at least one rev behind current so don't install from them.

• Note: build libax25 first then enable the run time Lib files so that the ax25 apps and ax25 tools use the ax25 library functions.
  • To enable run time Lib after libax25 is built, execute this as root:

echo "/usr/local/lib" >> /etc/ld.so.conf && /sbin/ldconfig

• Extract the three gzipped tar balls

tar -xvzf libax25-0.0.12-rc4.tar.gz
tar -xvzf ax25-apps-0.0.8-rc4.tar.gz
tar -xvzf ax25-tools-0.0.10-rc4.tar.gz

• for each tar ball build the source from each of these tar balls.
  • Do not need to be root until make install

cd <appropriate directory>
./configure
make
sudo make install

• After installing these 3 tar balls verify your AX.25 setup by running a packet spy
  • By installing a packet spy you will verify that your TNC, radio, cables & Linux AX.25 config are all working … and that's a big step.

• You will need a script to start the ax.25 service at bootup.
• The /etc/init.d/ax25 script points to /usr/local/etc/ax25/ax25-up to start and /usr/local/etc/ax25/ax25-down to stop the ax25 service.
  • It has four options [ start | stop | restart | status ]
• Start by placing the ax25 script found below in /etc/init.d/ and update the start up process by executing this command as root:

cd /etc/init.d
update-rc.d ax25 defaults 95

• NOTE according to Debian file location policy if the ax25-tools/ax25-apps are:
  • compiled from source, their config will be installed to /usr/local/etc/ax25
  • installed from a package, their config will be installed to /etc/ax25

• Below is a simple example of the scripts & parameters required to bring up the AX.25 interface.
• Need scripts:
  • /etc/init.d/ax25
  • /etc/init.d/ax25-up
  • /etc/init.d/ax25-down
• Need to edit these files:
  • /etc/ax25/axports
  • /etc/ax25/Lanparms

Unlike the Windows programs RMS Express & Airmail, Linux AX.25 does not know about different TNCs and their command modes. The kissattach program assumes the TNC is in KISS mode. You can ensure that the TNC is in KISS mode by modifying the AX.25 startup script before kissattach is run. In the example described in this wiki that would be in the ax25-up script in /etc/ax25 or /usr/local/etc/ax25 directories.

A brief comparison of TNCs can be found here

• Note that bringing up another network interface, like AX.25 on Linux, causes any daemons that broadcast out ALL ports to broadcast out the new port as well.
  • Examples: Samba, DropBox
  • Depending on what is installed on your Linux machine you will have to go to each daemon's config to specify which ports they're allowed to broadcast on.

• After running kissattach USB WiFi stops working
• Edit file /etc/default/ifplugd as shown below
  • original lines commented out

#INTERFACES="all"
INTERFACES=wlan0
#HOTPLUG_INTERFACES="all"
HOTPLUG_INTERFACES=wlan0