Multicast and Router mode

[Mike C]

Hi,

I have seen http://www.tinc-vpn.org/pipermail/tinc-devel/2010-October/000473.html
and so tried out for myself to see if multicast would work in tinc
using routing mode. I'm using tinc 1.0.19. My test involved sending a
ping out on 224.1.1.1 (as 224.0.0.0/24 is a special case), and while I
could see the traffic reaching the other tinc daemons, it never seemed
to go out to the local network. Turning on debugging, I could see the
packet reach the other site, but it doesn't get broadcast out onto the
network (wireshark shows nothing; I'm not expected any machines to
respond to the ping, it's just an easy way to send out something
multicast).

site1: 10.1.0.1/24

# ip route add 224.1.1.1/16 dev vpn
# ip route list
default via x.x.x.x dev eth0  metric 100
10.0.0.0/8 dev vpn  scope link
224.1.0.0/16 dev vpn  scope link
# ip route get 224.1.1.1
multicast 224.1.1.1 dev alpha  src 10.1.0.1
    cache <mc>

# ping -c 5 224.1.1.1

site3: 10.211.55.30/24

# ip route list
10.211.55.0/24 dev eth0  proto kernel  scope link  src 10.211.55.30  metric 1
192.168.0.0/16 dev vpn  scope link
10.0.0.0/8 dev vpn  scope link
default via 10.211.55.1 dev eth0 proto static

When I ping I see:

Feb 25 18:05:26 site1 tinc.vpn[22928]: Read packet of 98 bytes from
Linux tun/tap device (tun mode)
Feb 25 18:05:26 site1 tinc.vpn[22928]: Broadcasting packet of 98 bytes
from site1 (MYSELF)
Feb 25 18:05:26 site1 tinc.vpn[22928]: Sending packet of 98 bytes to
site2 (x.x.x.x port 1386)

Feb 25 18:05:26 site3 tinc.vpn[2790]: Received packet of 98 bytes from
site1 (y.y.y.y port 655)
Feb 25 18:05:26 site3 tinc.vpn[2790]: Writing packet of 98 bytes to
Linux tun/tap device (tun mode)
Feb 25 18:05:26 site3 tinc.vpn[2790]: Broadcasting packet of 98 bytes
from site1 (y.y.y.y port 655)

Looking at the code corresponding to "Broadcast packet", which from
what I can tell, sends the packet to other nodes, as well as sends it
to itself: send_packet(myself, packet);, however nothing shows up on
wireshark.

Ideas? I also see the same problem if I tried to do a broadcast ping
remotely vs locally: ping -c 5 10.211.55.255

Regards,

Mike