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Old January 31st 06, 04:02 PM posted to rec.radio.amateur.digital.misc
 
Posts: n/a
Default Can't run TCP/IP through AX.25 using Linux

Hi all,

I'm trying to setup a wireless link between two Linux using ConnexLink
900 MHz serial modems (http://www.aerocomm.com/Devices/link.htm). One
side (ali) is a regular PC running Debian Linux testing and the other
side (SLUG) is a NSLU2 running N7IPB's OpenSlug mod
(http://wetnet.net/).

The AX.25 link seem to work fine, I'm able to communicate between the
two sides with "call", but I can't figure out how to pass TCP/IP
through the link.

Anyone idea about what's going on?

Here's the relevant (I think) data from both hosts:
========================================
root@SLUG:~# cat /etc/ax25/axports
#Name Callsign baudrate paclen window Description
connex VA2JF-0 115200 1500 1 ConnexLink 900 MHz
root@SLUG:/etc/ax25# /usr/sbin/kissattach -l /dev/ttyUSB0 connex
172.25.25.2
AX.25 port connex bound to device ax0
root@SLUG:~# ifconfig ax0
ax0 Link encap:UNSPEC HWaddr
AC-82-64-94-8C-40-00-FF-00-00-00-00-00-00-00-00
inet addr:172.25.25.2 Bcast:172.25.255.255 Mask:255.255.0.0
UP BROADCAST RUNNING MTU:1500 Metric:1
RX packets:301 errors:0 dropped:0 overruns:0 frame:0
TX packets:61 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:10
RX bytes:17345 (16.9 KiB) TX bytes:2788 (2.7 KiB)
root@SLUG:~# /sbin/route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use
Iface
172.25.25.0 0.0.0.0 255.255.255.0 U 0 0 0
ax0
192.168.0.0 0.0.0.0 255.255.255.0 U 0 0 0
eth0
172.25.0.0 0.0.0.0 255.255.0.0 U 0 0 0
ax0
0.0.0.0 192.168.0.3 0.0.0.0 UG 0 0 0
eth0
root@SLUG:~# mheard
Callsign Port Packets Last Heard
VA2JF-1 connex 463 Mon Dec 19 21:08:44
root@SLUG:~# axparms -route list
callsign dev mode digipeaters

root@SLUG:~# ping -c 10 172.25.25.1
PING 172.25.25.1 (172.25.25.1): 56 data bytes

--- 172.25.25.1 ping statistics ---
10 packets transmitted, 0 packets received, 100% packet loss
========================================
root@ali:~# cat /etc/ax25/axports
# name callsign speed paclen window description
connex VA2JF-1 115200 1500 1 ConnexLink 900 MHz
root@ali:# kissattach -l /dev/ttyS1 connex 172.25.25.1
AX.25 port connex bound to device ax0
gfk@ali:~$ /sbin/ifconfig ax0
ax0 Link encap:AMPR AX.25 HWaddr VA2JF-1
inet addr:172.25.25.1 Bcast:172.25.255.255 Mask:255.255.0.0
UP BROADCAST RUNNING MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:165 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:10
RX bytes:0 (0.0 b) TX bytes:8085 (7.8 KiB)

gfk@ali:~$ /sbin/route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use
Iface
172.25.25.0 0.0.0.0 255.255.255.0 U 0 0 0
ax0
10.10.16.0 0.0.0.0 255.255.255.0 U 0 0 0
eth0
192.168.0.0 0.0.0.0 255.255.255.0 U 0 0 0
eth0
172.25.0.0 0.0.0.0 255.255.0.0 U 0 0 0
ax0
0.0.0.0 192.168.0.3 0.0.0.0 UG 0 0 0
eth0
gfk@ali:~$ mheard
Callsign Port Packets Last Heard
VA2JF connex 118 Sat Jan 28 16:44:54
gfk@ali:~$ sudo axparms -route list
callsign dev mode digipeaters

gfk@ali:~$ ping -c 10 172.25.25.2
PING 172.25.25.2 (172.25.25.2) 56(84) bytes of data.
From 172.25.25.1 icmp_seq=1 Destination Host Unreachable
From 172.25.25.1 icmp_seq=2 Destination Host Unreachable
From 172.25.25.1 icmp_seq=3 Destination Host Unreachable
From 172.25.25.1 icmp_seq=4 Destination Host Unreachable
From 172.25.25.1 icmp_seq=5 Destination Host Unreachable
From 172.25.25.1 icmp_seq=6 Destination Host Unreachable
From 172.25.25.1 icmp_seq=7 Destination Host Unreachable
From 172.25.25.1 icmp_seq=8 Destination Host Unreachable
From 172.25.25.1 icmp_seq=9 Destination Host Unreachable
From 172.25.25.1 icmp_seq=10 Destination Host Unreachable


--- 172.25.25.2 ping statistics ---
10 packets transmitted, 0 received, +10 errors, 100% packet loss, time
9020ms
, pipe 4
========================================

Thanks a lot and 73,
GFK's

PS: I was able to make the link work with PPP, but PPP requires a
full-duplex link. So I had to enable the full-duplex simulation of the
modem. This cut the available bandwidth in half. I'm trying to see if
AX.25 would perform better since it doesn't require full duplex.

--
Guillaume Filion, ing. jr
Logidac Tech., Beaumont, Québec, Canada - http://logidac.com/
PGP Key and mo http://guillaume.filion.org/

  #2   Report Post  
Old January 31st 06, 04:42 PM posted to rec.radio.amateur.digital.misc
Bob Bob
 
Posts: n/a
Default Can't run TCP/IP through AX.25 using Linux

Gidday

The setup looks okay at first glance,

Is a -0 SSID valid for a hardware address?

Is gfk@ali a root user? I had lots of trouble running TCP/IP AX25 apps
as a non priv user on my old SuSE system. Something about denying port
access. Didnt actually try "call" in user mode though.

Strange how SLUG's ifconfig doesnt show the hardware address. There has
to be an ARP system somewhere. ie the TCP/IP system must know which
hardware to bind to, then a map of the remote devices IP vs hardware
layer address. One of the first things that happens in a TCP/IP
conversation is for the sender to shout out on the network "who has this
IP address". The unit that has the address says "me me me!" which
advises the sender the correlation between hardware and IP.

Perhaps ARP is timing out? Hmmm. Well you can certainly add a static
entry for each end of the link. This will also make first data exchange
a little faster;

arp -a - lists the known table

On ali
arp -s 172.25.25.2 VA2JF-0

On SLUG
arp -s 172.25.25.1 VA2JF-1

On slug you also might like to set the HW address manually;
ifconfig ax0 hw ax25 VA2JF-0

Then try the ping again..

Tell us how you go..

OBTW I remember too that tcpdump doesnt work on an ax25 interface. You
might try that to see if you get any valid data. This will show the arp
conversation as well as IP Ethereal is also a nice GUI of this.

Cheers Bob W5/VK2YQA East Texas


wrote:

Hi all,

I'm trying to setup a wireless link between two Linux using ConnexLink
900 MHz serial modems (
http://www.aerocomm.com/Devices/link.htm). One
side (ali) is a regular PC running Debian Linux testing and the other
side (SLUG) is a NSLU2 running N7IPB's OpenSlug mod
(http://wetnet.net/).

The AX.25 link seem to work fine, I'm able to communicate between the
two sides with "call", but I can't figure out how to pass TCP/IP
through the link.

Anyone idea about what's going on?

Here's the relevant (I think) data from both hosts:
========================================
root@SLUG:~# cat /etc/ax25/axports
#Name Callsign baudrate paclen window Description
connex VA2JF-0 115200 1500 1 ConnexLink 900 MHz
root@SLUG:/etc/ax25# /usr/sbin/kissattach -l /dev/ttyUSB0 connex
172.25.25.2
AX.25 port connex bound to device ax0
root@SLUG:~# ifconfig ax0
ax0 Link encap:UNSPEC HWaddr
AC-82-64-94-8C-40-00-FF-00-00-00-00-00-00-00-00
inet addr:172.25.25.2 Bcast:172.25.255.255 Mask:255.255.0.0
UP BROADCAST RUNNING MTU:1500 Metric:1
RX packets:301 errors:0 dropped:0 overruns:0 frame:0
TX packets:61 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:10
RX bytes:17345 (16.9 KiB) TX bytes:2788 (2.7 KiB)
root@SLUG:~# /sbin/route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use
Iface
172.25.25.0 0.0.0.0 255.255.255.0 U 0 0 0
ax0
192.168.0.0 0.0.0.0 255.255.255.0 U 0 0 0
eth0
172.25.0.0 0.0.0.0 255.255.0.0 U 0 0 0
ax0
0.0.0.0 192.168.0.3 0.0.0.0 UG 0 0 0
eth0
root@SLUG:~# mheard
Callsign Port Packets Last Heard
VA2JF-1 connex 463 Mon Dec 19 21:08:44
root@SLUG:~# axparms -route list
callsign dev mode digipeaters

root@SLUG:~# ping -c 10 172.25.25.1
PING 172.25.25.1 (172.25.25.1): 56 data bytes

--- 172.25.25.1 ping statistics ---
10 packets transmitted, 0 packets received, 100% packet loss
========================================
root@ali:~# cat /etc/ax25/axports
# name callsign speed paclen window description
connex VA2JF-1 115200 1500 1 ConnexLink 900 MHz
root@ali:# kissattach -l /dev/ttyS1 connex 172.25.25.1
AX.25 port connex bound to device ax0
gfk@ali:~$ /sbin/ifconfig ax0
ax0 Link encap:AMPR AX.25 HWaddr VA2JF-1
inet addr:172.25.25.1 Bcast:172.25.255.255 Mask:255.255.0.0
UP BROADCAST RUNNING MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:165 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:10
RX bytes:0 (0.0 b) TX bytes:8085 (7.8 KiB)

gfk@ali:~$ /sbin/route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use
Iface
172.25.25.0 0.0.0.0 255.255.255.0 U 0 0 0
ax0
10.10.16.0 0.0.0.0 255.255.255.0 U 0 0 0
eth0
192.168.0.0 0.0.0.0 255.255.255.0 U 0 0 0
eth0
172.25.0.0 0.0.0.0 255.255.0.0 U 0 0 0
ax0
0.0.0.0 192.168.0.3 0.0.0.0 UG 0 0 0
eth0
gfk@ali:~$ mheard
Callsign Port Packets Last Heard
VA2JF connex 118 Sat Jan 28 16:44:54
gfk@ali:~$ sudo axparms -route list
callsign dev mode digipeaters

gfk@ali:~$ ping -c 10 172.25.25.2
PING 172.25.25.2 (172.25.25.2) 56(84) bytes of data.
From 172.25.25.1 icmp_seq=1 Destination Host Unreachable
From 172.25.25.1 icmp_seq=2 Destination Host Unreachable
From 172.25.25.1 icmp_seq=3 Destination Host Unreachable
From 172.25.25.1 icmp_seq=4 Destination Host Unreachable
From 172.25.25.1 icmp_seq=5 Destination Host Unreachable
From 172.25.25.1 icmp_seq=6 Destination Host Unreachable
From 172.25.25.1 icmp_seq=7 Destination Host Unreachable
From 172.25.25.1 icmp_seq=8 Destination Host Unreachable
From 172.25.25.1 icmp_seq=9 Destination Host Unreachable
From 172.25.25.1 icmp_seq=10 Destination Host Unreachable


--- 172.25.25.2 ping statistics ---
10 packets transmitted, 0 received, +10 errors, 100% packet loss, time
9020ms
, pipe 4
========================================

Thanks a lot and 73,
GFK's

PS: I was able to make the link work with PPP, but PPP requires a
full-duplex link. So I had to enable the full-duplex simulation of the
modem. This cut the available bandwidth in half. I'm trying to see if
AX.25 would perform better since it doesn't require full duplex.

--
Guillaume Filion, ing. jr
Logidac Tech., Beaumont, Québec, Canada - http://logidac.com/
PGP Key and mo http://guillaume.filion.org/

  #3   Report Post  
Old February 1st 06, 07:43 AM posted to rec.radio.amateur.digital.misc
Bob Bob
 
Posts: n/a
Default Can't run TCP/IP through AX.25 using Linux

Oh and another thing

PPP may be much more desirable because you can get huge compression
gains (ie using BSD or deflate compression) I use to use it over an old
28K8 modem connection and got data rates in the order of 20-30x when
moving logfiles around. As its compressed before it gets to the modem
you arent limited by the 115K2 DTE rate either..

Cheers Bob VK2YQA

wrote:

Hi all,

I'm trying to setup a wireless link between two Linux using ConnexLink
900 MHz serial modems (
http://www.aerocomm.com/Devices/link.htm). One
side (ali) is a regular PC running Debian Linux testing and the other
side (SLUG) is a NSLU2 running N7IPB's OpenSlug mod
(http://wetnet.net/).

  #4   Report Post  
Old February 1st 06, 09:29 PM posted to rec.radio.amateur.digital.misc
 
Posts: n/a
Default Can't run TCP/IP through AX.25 using Linux

Bob, thanks a lot for your help.

Is a -0 SSID valid for a hardware address?


That's what was given in an example I followed, but I changed VA2JF-0
to VA2JF-2 just to be sure. It's also easier to match each host to it's
IP address: VA2JF-1 has 172.25.25.1 and VA2JF-2 has 172.25.25.2.

Is gfk@ali a root user? I had lots of trouble running TCP/IP AX25 apps
as a non priv user on my old SuSE system. Something about denying port
access. Didn't actually try "call" in user mode though.


gfk@ali is not a root user, but I'm using sudo, so it shouldn't be a
problem. This is a good advice, however. I'll use root whenever I
playing with this.

There has to be an ARP system somewhere.


Indeed I think that the problem might be related to ARP. I used to
think that ARP was just used on Ethernet, but I learn something new
every day.

Here's what I got on ali:
ali:~# arp -an
[...]
? (172.25.25.2) at incomplete on eth0
ali:~# arp -H ax25 -i ax0 -s 172.25.25.2 VA2JF-2
ali:~# arp -an
[...]
? (172.25.25.2) at VA2JF-2 [ax25] PERM on ax0

Unfortunately, the slug is running busybox which is a very slimed down
Unix. It looks like busybox's ifconfig is not compatible with ax25,
hence the "Link encap:UNSPEC". I would like to try to compile a "real"
ifconfig but unfortunately the slug is running with 288KB of free disk
space. I'll need to transfer the system to a bigger flash drive when I
get some free time.

Also busybox doesn't have /usr/sbin/arp on the system, and
/proc/net/arp doesn't list any ax25 address...

OBTW I remember too that tcpdump doesnt work on an ax25 interface. You
might try that to see if you get any valid data. This will show the
arp conversation as well as IP


You're right:
ali:~# tcpdump -eni ax0
tcpdump: unknown data link type 3

I found a patch for tcpdump to work with ax25, but didn't tried it yet.
http://he.fi/archive/linux-hams/200509/0060.html

PPP may be much more desirable because you can get huge compression
gains (ie using BSD or deflate compression) I use to use it over an
old 28K8 modem connection and got data rates in the order of 20-30x
when moving logfiles around. As its compressed before it gets to the
modem you aren't limited by the 115K2 DTE rate either..


PPP requires full duplex and any radio link is inherently half-duplex.
I had to use "full duplex simulation" in the radio firmware which is
documented like this in the manual:
=====
Full Duplex: This mode restricts Client radios to transmitting on odd
numbered frequency hop bins and the Server to even numbered frequency
hop bins. Though the RF hardware is still technically half duplex, it
makes the transceiver seem full duplex. This can cause overall
throughputs to be cut in half. Note: All transceivers on the same
network must have the same setting for Full Duplex.
=== Ref: http://www.aerocomm.com/Docs/User_Manual_CL4490.pdf (p.16)

Also, the RF baud rate is fixed at 76.8 Kbps, so in "full duplex
simulation" it is effectively 33.6 Kbps. Even with compression, I
speculated that half duplex AX.25 would perform better for activities
such as web browsing where most of the heavy content (jpg images) is
already compressed.

I'll keep playing with this, thanks a lot for your help,
GFK's
--
Guillaume Filion, ing. jr
Logidac Tech., Beaumont, Québec, Canada - http://logidac.com/
PGP Key and mo http://guillaume.filion.org/

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Old February 2nd 06, 02:36 AM posted to rec.radio.amateur.digital.misc
 
Posts: n/a
Default Can't run TCP/IP through AX.25 using Linux

I found a patch for tcpdump to work with ax25, but didn't tried it yet.
http://he.fi/archive/linux-hams/200509/0060.html


I tried the patch, it works well. It's worth a try. The patch did not
apply cleanly, however. I had to apply some parts of the patch
manually. For those who don't want to do that, I've made a tarball of
the patched sources:
http://guillaume.filion.org/tcpdump-3.9.3-ax25-1.tar.gz

Here's the short readme:
Full infos about this patched tcpdump available at:
http://he.fi/archive/linux-hams/200509/0060.html

To build this version of tcpdump:

cd libpcap-0.9.3
../configure
make
cd ../tcpdump-3.9.3
../configure
make
../tcpdump -eni ax0

73,
GFK's
--
Guillaume Filion, ing. jr
Logidac Tech., Beaumont, Québec, Canada - http://logidac.com/
PGP Key and mo http://guillaume.filion.org/



  #6   Report Post  
Old February 2nd 06, 05:38 PM posted to rec.radio.amateur.digital.misc
Bob Bob
 
Posts: n/a
Default Can't run TCP/IP through AX.25 using Linux

Okay I see.. problems problems! grin

When I first started playing with TCP/IP over packet maybe 12 years ago
we did all we could to stop ARP broadcasts in our local subnet. All of
the users had static ARP tables for that reason. We also had static host
lookups. More recently I was involved in an IP over satellite
paging/short message system where our initial bandwidth allocation was
very small (3kb/sec). I made a lot of noise over that setup and
suggested that if the b/w was unchangable then we should use static ARP
tables. They increased the b/w instead, as a manual maintenance of an IP
networks ARP's is a huge task!

If you arent intent on using busybox you may want to try the Knoppix run
from CD version that has the amateur radio add-ons.

re PPP and HDX/FDX. Well in a way you are simply shifting the HDX
switching back to the computer instead of using the radio hardware. I'd
suspect that in the end you wouldnt do any better. I am however prepared
to be shot down over this!

I wonder if SLIP is any better handling HDX? It has less protocol
overhead as well.. (from memory) Not sure about compression though.

I have an application of sorts for this same mind of thing. My mother in
law lives about 500 yards away just over the brow of a hill. There are
also lots of trees! I doubt 2.4GHz will work and was looking at
something with at least 115K throughout to connect her PC to our
network. What has been your experience with the 900MHz gear and how well
does it do with path obstacles? Oh and what did the units cost?

Tnxs for the info on tcpdump. One day when I get back to radio...

Cheers Bob W5/VK2YQA East Texas

wrote:

Bob, thanks a lot for your help.

  #7   Report Post  
Old February 4th 06, 10:10 PM posted to rec.radio.amateur.digital.misc
 
Posts: n/a
Default Can't run TCP/IP through AX.25 using Linux

Hi Bob,

I compiled net-tools on the slug and I now get this, which looks much
better:
root@slug:~# ifconfig ax0
ax0 Link encap:AMPR AX.25 HWaddr VA2JF-2
inet addr:172.25.25.2 Bcast:172.25.255.255 Mask:255.255.0.0
UP BROADCAST RUNNING MTU:1500 Metric:1
RX packets:52 errors:0 dropped:0 overruns:0 frame:0
TX packets:22 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:10
RX bytes:4238 (4.1 Kb) TX bytes:898 (898.0 b)

net-tools also provided a version of arp. When I use it, though, I get
this strange behavior:
=====
root@slug:~# arp -an
? (192.168.0.5) at 00:01:53:80:57:E6 [ether] on eth0
root@slug:~# arp -H ax25 -i ax0 -s 172.25.25.1 VA2JF-1
root@slug:~# arp -an
? (172.25.25.1) at * [ax25] PERM on -
? (192.168.0.5) at 00:01:53:80:57:E6 [ether] on eth0
root@slug:~# cat /proc/net/arp
IP address HW type Flags HW address Mask Device
172.25.25.1 0x3 0x6 * ax0
192.168.0.5 0x1 0x2 00:01:53:80:57:E6 * eth0
=====
I'm not sure if this is related to my version of arp or the kernel but
I have a feeling that this is at the heart of the problem...

If you arent intent on using busybox you may want to try the Knoppix
run from CD version that has the amateur radio add-ons.


The slug is in fact a NSLU2 from Linksys, which is not much bigger than
my hand. There's no CD player on this, so I'm stuck with busybox if I
want to use the NSLU2. http://xrl.us/NSLU2

re PPP and HDX/FDX. Well in a way you are simply shifting the HDX
switching back to the computer instead of using the radio hardware.
I'd suspect that in the end you wouldnt do any better. I am however
prepared to be shot down over this!


When working in FDX simulation, the radio hardware does the HDX
switching 50:50. This is fixed and cannot be changed. I hope that AX.25
will switch it dynamically, sometimes 90:10 sometimes 70:30, so that I
can get better performance when I need it. I'm not sure if it's worth
the trouble, however.

I have an application of sorts for this same mind of thing. My mother
in law lives about 500 yards away just over the brow of a hill. There
are also lots of trees! I doubt 2.4GHz will work and was looking at
something with at least 115K throughout to connect her PC to our
network. What has been your experience with the 900MHz gear and how
well does it do with path obstacles? Oh and what did the units cost?


I bought the Connexlink radios a couple months ago from Mouser. I
bought the starter pack (Includes 1 server and 1 client Unit, RS-232
cables, Antennas, Power Supplies and Software) for US$225 (Mouser Stock
No. 814-CL4490-232-SP). About 1 week after ordering, I got a phone call
from a ConnexLink technician asking for informations about my project
and giving me his phone number if I needed any help.

My link is similar to yours, it's to my mother's house and I'm afraid
that 2.4 GHz is not going to cut it unless I install a 100' tower on
each side. It's 2.9 Km long (1.8 miles). I have a hill and lots of
trees doing obstruction. Take a look at my path profile, I'm about at
F0.9. It's made with Radio Mobile:
http://www.cplus.org/rmw/english1.html

Path profile scaled 10:1:
http://guillaume.filion.org/80211lin...l-900-10-1.gif

Path profile not scaled (1:1):
http://guillaume.filion.org/80211lin...el-900-1-1.gif

I haven't tested the hardware outside yet -- it's winter time here and
I don't feel like climbing on the roof top full of snow. The specs says
it can do 32 Km LOS with the stock antennas. I'm not LOS, but with yagi
antennas replacing the stock antennas, I'm pretty sure that I could
have a decent link.

Common wisdom says that 900 MHz is too crowded for any good use, but I
live in the country and there is not a lot of 900 MHz activity around
here. The ConnexLink uses Frequency Hopping Spread Spectrum so it's
more resistant to QRM. Your mileage may vary...

Some links:
http://www.mouser.com/aerocomm/
http://www.aerocomm.com/Devices/link.htm

73
GFK's
--
Guillaume Filion, ing. jr
Logidac Tech., Beaumont, Québec, Canada - http://logidac.com/
PGP Key and mo http://guillaume.filion.org/

  #8   Report Post  
Old February 5th 06, 12:09 AM posted to rec.radio.amateur.digital.misc
 
Posts: n/a
Default Can't run TCP/IP through AX.25 using Linux

Hi again,

I did some tcpdump and it definitly looks like an ARP problem.

# ./tcpdump -envi ax0
tcpdump: listening on ax0, link-type AX25 (AX.25), capture size 96
bytes

[... root@slug:~# ping 172.25.25.1 ...]
17:30:01.703620 VA2JF-2 -6: Res 3, C/R 0, UI, ?, pf 0, length 101:
(tos 0x0, ttl 64, id 0, offset 0, flags [DF], proto: ICMP (1), length:
84) 172.25.25.2 172.25.25.1: ICMP echo request, id 1691, seq 0,
length 64
[... Notice the "VA2JF-2 -6" instead of "VA2JF-2 VA2JF-1" ...]

[... root@ali:~# ping 172.25.25.2 ...]
17:31:24.033354 VA2JF-1 VA2JF-2: Res 3, C/R 0, UI, ?, pf 0, length
101: (tos 0x0, ttl 64, id 0, offset 0, flags [DF], proto: ICMP (1),
length: 84) 172.25.25.1 172.25.25.2: ICMP echo request, id 6003, seq
1, length 64
[... I never get an answer from slug, I guess it's because slug's arp
table doesn't contain ali's address ...]

I'll get in contact with the creator of this kernel.

73
GFK's
--
Guillaume Filion, ing. jr
Logidac Tech., Beaumont, Québec, Canada - http://logidac.com/
PGP Key and mo http://guillaume.filion.org/

  #9   Report Post  
Old February 5th 06, 02:41 AM posted to rec.radio.amateur.digital.misc
Joseph Fenn
 
Posts: n/a
Default Can't run TCP/IP through AX.25 using Linux

Dont know about you guys, but since I still use an old 8 bit
Commodore128 computer I do all my packeting with the software
DIGICOM128 AND IT WAS WRITTEN BY THE GERMANS WAY BACK.
I use only the VHF band for military packet relays from
Ft Huachuca Az to Schofield Bks here in Honoululu.
Joe ABM6JF


************************************************** ********
* Ham KH6JF AARS/MARS ABM6JF QCWA WW2 VET WD RADIO SYSTEM*
* Army MARS PRECEDED by AARS (Army Amateur Radio System) *
* Hi State ARMY MARS COORDINATOR *
************************************************** ********


On Sat, 4 Feb 2006 wrote:

Hi again,

I did some tcpdump and it definitly looks like an ARP problem.

# ./tcpdump -envi ax0
tcpdump: listening on ax0, link-type AX25 (AX.25), capture size 96
bytes

[... root@slug:~# ping 172.25.25.1 ...]
17:30:01.703620 VA2JF-2 -6: Res 3, C/R 0, UI, ?, pf 0, length 101:
(tos 0x0, ttl 64, id 0, offset 0, flags [DF], proto: ICMP (1), length:
84) 172.25.25.2 172.25.25.1: ICMP echo request, id 1691, seq 0,
length 64
[... Notice the "VA2JF-2 -6" instead of "VA2JF-2 VA2JF-1" ...]

[... root@ali:~# ping 172.25.25.2 ...]
17:31:24.033354 VA2JF-1 VA2JF-2: Res 3, C/R 0, UI, ?, pf 0, length
101: (tos 0x0, ttl 64, id 0, offset 0, flags [DF], proto: ICMP (1),
length: 84) 172.25.25.1 172.25.25.2: ICMP echo request, id 6003, seq
1, length 64
[... I never get an answer from slug, I guess it's because slug's arp
table doesn't contain ali's address ...]

I'll get in contact with the creator of this kernel.

73
GFK's
--
Guillaume Filion, ing. jr
Logidac Tech., Beaumont, Québec, Canada -
http://logidac.com/
PGP Key and mo http://guillaume.filion.org/


  #10   Report Post  
Old February 5th 06, 10:54 PM posted to rec.radio.amateur.digital.misc
Bob Bob
 
Posts: n/a
Default Can't run TCP/IP through AX.25 using Linux

I wonder if slug has an issue with dashes in the hardware address?
Either that or it is smart enough to notice the first 5 chars of the
hardware address are the same source dest. As you say though it isnt
working! Looks like you are getting closer!

Okay on the 50:50 half duplex timing of the boxes. That seems kind of a
strange way to do it. Would have expected the manufacturer to use
dynamic b/w allocation. I had a quick look at SLIP/CSLIP but didnt
really establish how effective it was on HDX. I assume that ppp is
unusable because of the backgound handshaking that goes on (ipcp etc)?
Is it that or timeouts and retries at the IP layer?

Tnxs for the info on your purchase. I dont want to spend lots of dollars
on my attempt. Would rather invest in 2nd hand than new equipment. The
MIL is using dial-up at the moment so it isnt exactly urgent. I have a
mind to use one of the scrap microwave radios from work but they start
at 2.4GHz. (We manufacture data equip up to 12GHz and DS1 through E3) My
path actually looks a lot better than yours though!

Cheers Bob

wrote:

Hi again,

I did some tcpdump and it definitly looks like an ARP problem.

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