Re Correlation between axports portname and interface name..

I hope I have this right, I kind of just arrived at the notion it may be!

- As mentioned AX25 on Linux is a TCP/IP implementation. TCP/IP is in
fact part of the OSI 7 layer model. You can regard the first layer as
being physical hardware, the second as one having "hardware addresses",
the third having "IP" addressing, the 4th TCP and so on.

- In ethernet networking the physical hardware is pretty obvious, as is
the packet world. The hardware addressing layer in the ethernet world is
the MAC address of the interface. (HWAddr) See my "ifconfig" dump below.
(Its that 000 etc number)

- In the AX25 world for amateurs the hardware address is the callsign
plus SSID. eg VK2YQA-3. On my packet box I actually have three packet
ports (sm0, 1 & 2) and their associated hardware addresses (VK2YQA-1,
VK2YQA-2, VK2YQA-3)

- When you start/setup the hardware interface whether it be a kiss TNC,
baycom device or soundcard modem you define the low level interface, the
IP address and the hardware address. The hardware address is also
visible in /etc/ax25/axports as this contains the lookup table for the
"pure/standard" AX25 connect mode port to use. The port name you use for
linpac/call is not an IP port.You can think of the "normal" AX25 mode
working at the HWAddr layer only and IP sits on top of that. If you want
to run IP over AX25 you use the standard internetworking stuff available
on the Linux box. You could web browse over AX25 but boy would it be slow!

- And again on my packet box I also have three IP address ranges and
subnets for the interfces (44.136.0.1/255.255.255.0,
44.136.0.2/255.255.255.0, 44.136.0.3/255.255.255.0) and the associated
names in axports being the same as the low level names (sm0-2). They
equally could have been "AFSK1200", "Q15X25" & "AFSK300"

- Different hardware devices have different initial setup. kissattach
and kissparams are used for KISS TNCs, sethdlc for baycom and so on. The
userspace soundmodem is preconfigured using a confoguration file. Along
with defining hardware params like ports and interrupts, these kind of
startup the low level linux interface and may or may not contain IP and
hardware address/name information. Using "ifconfig" then allows you to
specify or re-specify the hwaddr and IP address as needed. It also
finally "brings up" or enables the interface. I would guess that if you
werent interested in IP you maybe able to leave it unconfigured but be
aware of the correlation between the AX25 hardware address
(callsign+ssid) in /etc/ax25/axports and the port name/naumber used by
linpac etc.

I am prepared to be shot down on this but so far it looks good to me!

Cheers Bob



eth0
Link encap:Ethernet HWaddr 000:B7:B2:C3:B0
inet addr:192.168.0.250 Bcast:192.168.0.255 Mask:255.255.255.0
inet6 addr: fe80::2d0:b7ff:feb2:c3b0/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:8335407 errors:2 dropped:0 overruns:0 frame:2
TX packets:8471881 errors:72 dropped:0 overruns:0 carrier:72
collisions:147699 txqueuelen:100
RX bytes:772321466 (736.5 Mb) TX bytes:1379313960 (1315.4 Mb)
Interrupt:9 Base address:0xb800 Memory:e0800000-e0800038