From: Kjell Jarl (erva@csconsultants.net)
Date: Wed May 03 2000 - 00:39:40 EEST
Hi Tomi,
Thanks, I think this explains to me. I have not noticed any problems
though, and my users have not said anything - about not getting in at
least.
I have seen that welcome message, some time ago, but the connection has
went through. I cannot easilly test this as I almost all the time has
some one connected to the cluster so the link is established. Next time
I notice no link (my outgoing are over plain ax.25 not netrom so there
should be oportunities) I will try and see what the response really is.
73
Kjell
axports:
scc0 SM7GVF 9600 255 7 Radio port
nrports:
netrom SM7GVF-5 LINUX 235 Switch Port
netdx SM7GVF-6 DX 235 Dx port
netconv SM7GVF-3 CONV 235 Convers port
ax25d.conf:
[SM7GVF-5 VIA scc0]
NOCALL * * * * * * L
default * * * * 14400 * - root /usr/sbin/node node
#
<netrom>
NOCALL * * * * * * L
default * * * * * * - root /usr/sbin/node node
#
[SM7GVF-6 VIA scc0]
NOCALL * * * * * * L
default * * * * * * - clx_us /usr/local/clx/bin/net_usr net_usr -x %s
#
<netdx>
NOCALL * * * * * * L
default * * * * * * - clx_us /usr/local/clx/bin/net_usr net_usr -x %s
Tomi Manninen wrote:
>
> On Mon, 1 May 2000, Kjell Jarl wrote:
>
> > I do the same, have both netrom and port call the same, and letting node
> > respond to ax.25 user connects to the same SSID.
> > It seems to work, and makes it obviuos for users what to connect to.
> > Maybe some one could elaborate on why not to do it?
>
> If you let an application like LinuxNode answer to L2 requests with the
> same callsign that is used for internode NET/ROM traffic you can have
> problems like this:
>
> Your neighbor node wants to send NET/ROM traffic to you. It needs to open
> a L2 connection to you and it uses the callsign shown on your NODES
> broadcasts (== first nrports callsign == HWaddr for nr0). But now you have
> configured ax25d to listen for that callsign and to lauch "node". Linux
> has no way of knowing so it does what it is told and node is lauched. Node
> then sends it's welcome text and the trouble begins...
>
> What happens next depends on what is at the other end of the connection
> (the neighbor) and it ranges from a minor inconvenience through lots of L2
> disconnetions and lost L3 frames to an avalanche of "invalid command"
> messages flooding the band.
>
> Ever wondered why node software like BPQ and TheNet never send a welcome
> message...? :-) (And no, just dropping the welcome text from LinuxNode is
> not a solution though I have been thinking of adding that as an option
> to node.)
>
> The same thing applies to AX.25 interface callsigns (those in axports) if
> you expect to have incoming TCP/IP traffic using Virtual Circuit mode.
>
> --
> Tomi Manninen Internet: yfilg@mcdermott.com
> OH2BNS AX.25: jwtrszl.tjwve@suberic.net
> KP20ME04 Amprnet: terhi.victor@logonet.com
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