Cannot establish an l2tpv3 tunnel between two ERLs

Well,

   I have spent quite some time trying to establish a working l2tpv3 tunnel bridgin two vlans at two different ERLs.

   There si not much information of examples out there about doing this sort of thing, so it may very well be that I am totally off track.

   I started using my already-established IPSEC site-to-site vpn with a GRE tunnel, using loopback interface addresses, and the GRE tunnel addresses. Finally I ditched the IPSEC VPN and used directly the public (WAN) IP addresses of the routers.

   All to no avail. I can see no ARP traffic going from one LAN to the other. Quite frankly, I am out of ideas to make this work. Is L2TPV3 working at all on ERL?

  My interface configuration is as follows:

 bridge br0 {
     promiscuous enable
 }

 ethernet eth1 {
     address 192.168.2.62/20
     description "Intranet"
     duplex auto
     speed auto
     vif 565 {
         address x.x.x.x/23
         description MYDESCRIPTION
         firewall {
             in {
                 name WAN_IN
             }
             local {
                 name WAN_LOCAL
             }
         }
     }
 }
 ethernet eth2 {
     address 172.16.203.1/24
     description Local
     duplex auto
     speed auto
     vif 10 {
         bridge-group {
             bridge br0
         }
     }
 }
 l2tpv3 l2tpeth0 {
     bridge-group {
         bridge br0
     }
     encapsulation ip
     local-ip x.x.x.x
     mtu 1300
     peer-session-id 1
     peer-tunnel-id 1
     remote-ip y.y.y.y
     session-id 1
     tunnel-id 1
 }

   Interface eth1.565 is my WAN interface. 

   The other ERL has a similar/mirror configuration (slightly simpler in the WAN interface)

   This was my last attampet at making this work, after trying it over an IPSEC protected VPN.

   I have two computers attached to VLAN 10. One on one ERL and the other on the other ERL. I cannot ping one from the other or connect in any way. In fact, I do not see ARP requests traverse the tunnel.

   What is missing in the configuration?