After dealing with an e-mail query regarding the changing of a default
AX.25 port parameter, I thought I'd pass the information onto the list
too. This will be especially useful for people who are still missing the
"axparms -parms" option. If you are running a bog standard Linux 2.0.x,
1.3.x (!!!) or Linux 2.0.x with any ax25-module less than 10, or even
Linux 2.1.0 to 2.1.8 then this doesn't affect you ... but it will one day.
The below only applies to AX.25, with NET/ROM and ROSE the parameters are
somewhat easier to change, and I will mention them briefly later.
Let us take an example. By default an AX.25 connection will be dropped
after ten minutes of inactivity, this is probably fine for most people,
but for ROSE interlinks it is fatal, or at the very least annoying. This
timeout is governed by the Idle Timer, and setting it to zero will switch
it off. So how do I change the Idle Timer on device ax1 to zero ?
You need the sysctl interface to do this, if you look in the file
linux/Documentation/networking/ax25.txt you will see that each parameter
for each port is changeable. So do something like:
cat /proc/sys/net/ax25/ax1.parms > /etc/ax25/ax1.parms
Note that the name of the file /proc/sys/net/ax25/ax1.parms reflects the
name of the device. My choice of /etc/ax25/ax1.parms is simply an
arbitrary one. In it you will see a list of numbers that reflect the
values listed in ax25.txt.
Edit the file /etc/ax25/ax1.parms and change the 11th number (Idle
Timeout) to 0, save the file.
Then in your AX.25 startup file do:
cat /etc/ax25/ax1.parms > /proc/sys/net/ax25/ax1.parms
If you do a "cat /proc/sys/net/ax25/ax1.parms" you should see parameter 11
is still 0. Your AX.25 connections on device ax1 will stay up forever or
until hell freezes over, whichever comes first. And before anyone whinges,
that wasn't meant as a religeous comment, it is simply a figure of speech,
OK.
And that is it.
I do intend to do some tweaking of this interface in the future to make
(for example) /proc/sys/net/ax25/ax1.parms 11th parameter into
/proc/sys/net/ax25/ax1/idle_timeout or something similar, and so on.
With NET/ROM and ROSE each parameter exists in its own suitably named
"file", so changing one parameter involves writing a value to one
filename, and with none of the nonsense seen for AX.25 above.
I bet that was as clear as mud :-)
Jonathan
-- +----------------------------------+---------------------------------------+ | e-mail: gwtkuq@alcas.nl | Telephone: +44 (0) 973 695261 | +----------------------------------+---------------------------------------+ | Author of Linux kernel AX.25, NET/ROM and Rose. | +--------------------------------------------------------------------------+