I am having a problem where the tunnel works fine but when i leave ot without traffic for a couple of hours, after that it cannot be reached by ping from any ipv6 address (all the pings dropped and the traceroute reachs the other side of the tunnel), however when i generate a single IPv6 packet going out from my network the connection is restored and is reacheable again. I see the heartbeats going out each one minute. Has anybody experienced that? Patricio