Re: Compass udrc kernel panic

Basil Gunn
 

Curt, WE7U <curt.we7u@...> writes:

On Thu, 6 Dec 2018, Annaliese McDermond wrote:

If you?d like to know my offhand guess as to what?s happening, I?d
guess that Chromium is trying to do a broadcast to all interfaces for
some reason. Once you load the ax25 stack, the packet modem becomes
a network interface. This broadcast packet is probably triggering a
bug in the ax25 stack due to it having some sort of freaky address
(or more accurately no address) by the time it gets there. But this
is just a wild guess from hearing the symptoms.
Check Samba as well if it's loaded and running. It's a known
contributor to "talk to all interfaces" problems.
When I bring up an AX.25 machine I always install iptables & block the
following 3 addresses on both ax0 & ax1 interfaces. I noticed these
addresses being broadcast/multicast while looking at a traffic spy of my
RF interfaces.

iptables -A OUTPUT -o ax0 -d 224.0.0.22 -p igmp -j DROP
iptables -A OUTPUT -o ax0 -d 224.0.0.251 -p udp -m udp --dport 5353 -j DROP
iptables -A OUTPUT -o ax0 -d 239.255.255.250 -p udp -m udp -j DROP

iptables -A OUTPUT -o ax1 -d 224.0.0.22 -p igmp -j DROP
iptables -A OUTPUT -o ax1 -d 224.0.0.251 -p udp -m udp --dport 5353 -j DROP
iptables -A OUTPUT -o ax1 -d 239.255.255.250 -p udp -m udp -j DROP

224.0.0.22 is used for IGMPv3 (multicast) protocol
224.0.0.251 is Bonjour/mDNS request coming out of the Avahi daemon
239.255.255.250 is Simple Service Discovery Protocol (SSDP) for uPNP
detection

I agree with Curt that Samba & dropbox will broadcast on all
network addresses but you can fix both of these with proper
configuration of the app.

/Basil

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