no answer from peer at he.net

[rsokoll]

Hi,

I use an Ubiquity ER-X and to my best knowledge, everything is configured properly. Tunnel end is 216.66.80.30 which is tserv1.fra1.he.net.
The tunnel interface is up. But I cannot see (tcpdump) any answers to icmp6 ping requests to anywhere. When I tcpdump on the IPv4 interface for traffic from/to 216.66.80.30, I only see outgoing packets. My router's IP is set correctly in the web interface at tunnelbroker.net.

Any ideas?