New subject: 44Net Digest, Vol 2, Issue 159

7 Oct 2013

...
  Subject:
 Re: [44net] 44Net Digest, Vol 2, Issue 159
 From:
 sp2lob &lt;sp2lob(a)tlen.pl&gt;
 Date:
 10/06/2013 12:43 AM

 To:
 AMPRNet working group &lt;44net(a)hamradio.ucsd.edu&gt;

 Hello Rob et al,

 In my system I've similar setup.

 1. tun0  - tunnel to my JNOS
 2. tunl0 - tunnel to AMPRNet

 Both have assigned same IP - 44.165.2.2
 I do not observe anything suspicious.

 What kind of issue do you encounter, please?

 Best regards.
 Tom - sp2lob Tom,

Check this:
cat /proc/net/igmp

Idx     Device    : Count Querier       Group    Users Timer Reporter
1       lo        :     1      V3
                                 010000E0     1 0:00000000               0
2       eth0      :     1      V3
                                 010000E0     1 0:00000000               0
3       tunl0     :     2      V3
                                 090000E0     1 0:00000000               0
                                 010000E0     1 0:00000000               0
4       net0      :     1      V3
                                 010000E0     1 0:00000000               0

As you can see, the 224.0.0.9 address is at the tunl0 interface.
When I start the daemon after the net0 interface is created (tun0 in your case)
the address gets added to net0 only, and not to tunl0.   Therefore the daemon
does not receive the 224.0.0.9 multicasts (only 224.0.0.1 which everyone gets).

I don't know what the algorithm is to select the interface when there are multiple
interfaces with the same address.   It looks like it picks the one with the highest
index.  The function to add a multicast address cannot specify the interface
directly.

Rob