switch mode, how to give a public IP behing a NAT

[Cédric Lemarchand]

Hi all,

I use tinc since 2 years between my MPLS sites in router mode, works
like a charm.
Today i am trying to make an ethernet bridge beetween 2 sites for video
conference needs, the raison is that 1 side is behind nat, and i dont
have access on the gate, other side is on public range. Because off H323
that doesn't handle unconfigured NAT, i would like to give a public IP
to the video device.

Video (V1) <==> Node 1 (N1) <=GATE / NAT=> WWW <=GATE / PUB=> Node 2 (N2)


V1 has fixed public IP in the range of N2, and the ip of GATE has
default gateway.
N1 has eth0 on the lan, br0 is a bridge of eth1 (where i want to plug
the video device) and the tinc interface.
N2 has is public IP on br0, which is  a bridge of eth0 and the tinc
interface.

The Tinc configuration, very simple in my case, seams ok, logs shows
both sides are well connected, 'brctl showmacs' looks good, showing mac
address of remote sites ect ...
Packet capture on both br0 interfaces show broadcast traffic crossing
the VPN.

When i try to ping GATE from V1, i can see arp request crossing the VPN
(on both br0 interfaces), packet capture on GATE show the arp reply, but
this arp reply never come back on the bridge br0 of N2. (N2 is using
GATE has default gateway too)

I am not sure the problem is tinc related but i failed to found why it
doesnt work, this is making me crazy.


Any ideas would be appreciated.

Regards,


--
Cédric