Ubuntu 14.04: Unable to ping endpoint

[simguru]

Hi,

I've been working with my upstream ISP on getting protocol 41 working correctly so I can setup an IPv6 tunnel. Protocol 41 SEEMS to be working because I can traceroute to the tunnel endpoint using protocol 41.

$ sudo traceroute -P 41 -n 184.105.253.14
traceroute to 184.105.253.14 (184.105.253.14), 30 hops max, 60 byte packets
1  10.42.0.1  2.596 ms  1.754 ms  2.150 ms
2  10.143.1.62  0.961 ms  0.887 ms  0.870 ms
3  198.133.178.254  1.038 ms  0.992 ms  0.985 ms
4  209.203.112.109  1.379 ms  1.364 ms  1.361 ms
5  66.192.241.78  19.435 ms  19.019 ms  19.020 ms
6  206.223.118.37  19.455 ms  19.362 ms  21.301 ms
7  184.105.213.118  51.066 ms  50.333 ms  49.848 ms

Any other nodes on the network can't accomplish this traceroute. However, when a I do a ping6 on my endpoint, I get nothing:

$ ping6 2001:470:1f10:98c::1
PING 2001:470:1f10:98c::1(2001:470:1f10:98c::1) 56 data bytes
^C
--- 2001:470:1f10:98c::1 ping statistics ---
4 packets transmitted, 0 received, 100% packet loss, time 3022ms

And a tcpdump of protocol 41 traffic:

$ sudo tcpdump -ns 0 proto 41
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth0, link-type EN10MB (Ethernet), capture size 65535 bytes
09:51:48.922381 IP 10.42.0.15 > 184.105.253.14: IP6 2001:470:1f10:98c::2 > 2001:470:1f10:98c::1: ICMP6, echo request, seq 1, length 64
09:51:49.929286 IP 10.42.0.15 > 184.105.253.14: IP6 2001:470:1f10:98c::2 > 2001:470:1f10:98c::1: ICMP6, echo request, seq 2, length 64
09:51:50.937279 IP 10.42.0.15 > 184.105.253.14: IP6 2001:470:1f10:98c::2 > 2001:470:1f10:98c::1: ICMP6, echo request, seq 3, length 64
09:51:51.945277 IP 10.42.0.15 > 184.105.253.14: IP6 2001:470:1f10:98c::2 > 2001:470:1f10:98c::1: ICMP6, echo request, seq 4, length 64
4 packets captured
4 packets received by filter
0 packets dropped by kernel

And my /etc/network/interfaces file:

auto eth0
iface eth0 inet static
        address 10.42.0.15
        netmask 255.255.248.0
        gateway 10.42.0.1
        dns-nameservers 10.192.22.74 10.192.22.76
iface eth0 inet6 static
        address 2001:470:1f11:98c::c0de
        netmask 64

auto he-ipv6
iface he-ipv6 inet6 v4tunnel
        address 2001:470:1f10:98c::2
        netmask 64
        endpoint 184.105.253.14
        local 10.42.0.15
        ttl 255
        gateway 2001:470:1f10:98c::1

Everything I can see in the configuration seems to be OK. This is not the first tunnel I've deployed and I haven't seen this behavior.

1) Is there a better way of verifying protocol 41 firewall/NAT configuration than the traceroute I ran?
2) Is there anything I could possibly be overlooking.

Any and all suggestions and hints are greatly appreciated.

[cholzhauer]

I'm no ubuntu expert, so I can't verify your setup, but it looks reasonably correct.

However, your packet capture only shows traffic one way; nothing looks to be coming back in