Linux-Hams archive - October 1998: Re: TCPIP over AX25

Re: TCPIP over AX25

Michael Schwarz (dbop.neio@mx.dy.fi)
Mon, 5 Oct 1998 23:00:08 -0500 (CDT)

This doesn't sound like a problem. This sounds right to me. In
order to send an IP datagram the IP address must be bound to the
underlying network's addressing scheme. In an ethernet this is the
NIC address. In an AX.25 network this is the callsign of the TNC
node. "ARP" is the Address Resolution Protocol. It shoudl be
sending a broadcast carrying your IP address and callsign and
requesting the IP address it wants to send an IP datagram to. When
that station hears its own IP address it should respond with an ARP
reply carrying your IP address and callsign, its IP address AND ITS
CALLSIGN. Once you have this, you can send IP datagrams directly to
that node.

I'm still working to set up IP over AX.25 under linux myself, so I'm
not an expert in the details, but this is how IP on ethernets,
token-ring networks, and MS-DOS NOS/NET/JNOS AX.25 hosts works.

Note that this has nothing to do with routing. If you are trying to
reach and address beyond your "local" network, the IP address your
machine is asking to bind will not be the ultimate destination
address, but rather the "next-hop" address (the gateway address).

Others can help you (and me!) with the linux particulars, but I can
help with anything else IP if you'd like.

I hope this helps...

--
"Pm fvb jhu ylhk aopz, fvb hyl h jyfwav mylhr!"
               - Caesar VII
terhi.victor@logonet.com  iuxxn.bsuv@activebooking.com
Michael A. Schwarz
PGP 5.0 or 2.6.2 public key available on request


On Mon, 5 Oct 1998, Willi Gruber wrote:


> Hi all,
> 
> I have problem to make a regular TCPIP call over AX25.
> If I try to telnet or ftp to remote node, on the monitor
> I see that my node is sending:
> 
> Port 1: AX25: OK1FWG-15->QST <UI> pid=ARP
> source:
> destination:
> 
> The addresses of source and destination are correct, but how
> to replace the QST of my default node? I had setup it via
> axparms -route etc. I can list the route table but on every
> attempt it sends out the above mentioned frame with the QST.
> 
> 73, Willi, OK1FWG
>