[nos-bbs] AXUDP/AXIP - resolving (not) DOMAIN NAMES in autoexec.nos

[Maiko Langelaar (ve4klm)]

Greetings,

I just thought I would pass this tidbit of information out to the
group. Did you know that if you try to pass a hostname in any of the
autoexec.nos commands, resolution of that hostname will fail.

One could put the entry in their local DNS (domain.txt) file, but that
is not practical in (most) cases where you would need to go out to the
internet to get the information anyways.

The way JNOS works is that DNS query is not available until the entire
autoexec.nos has been loaded and JNOS has entered it's main command loop,
ready to accept commands at the console.

So what do we do ? Let's look at an AXUDP link to a DYNDNS remote host.

Suppose you have the following entry in your autoexec.nos :

   attach axudp werner 256 ve4wws.dyndns.org
   ifconfig werner desc "wormhole to ve4wws"

After JNOS has finished loading autoexec.nos and is ready, you will
probably not see the interface (port) called 'werner' when you run
the ifconfig command at the console, or the Ports command at the
mailbox prompt.

If the initial domain name query for 've4wws.dyndns.org' fails (which
it will) when you run the attach, the interface is not created, and the
subsequent ifconfig fails as well.

The only practical solution is to schedule the attach AFTER the JNOS
system is up and running. You can use the JNOS 'at' command to run the
attach and ifconfig a bit later. So, instead, you SHOULD use something
like the following in your autoexec.nos :

   at now+0001 "attach axudp werner 256 ve4wws.dyndns.org"
   at now+0002 "ifconfig werner desc \"wormhole to ve4wws\""

Of course that means you have to wait 1 minute after JNOS has restarted
to make use of the AXUDP link and yet another minute after that to see
the description for the port.

K2MF (Barry) has modified his MFNOS 'at' command to accept the use of
seconds, ie: 'at ss', which I'm going to implement as well as a future
feature. That way instead of waiting a minute or two, it's just a matter
of waiting a few seconds instead.

That will work much better.

Maiko Langelaar / VE4KLM