I had IPv6 working great on my Ubuntu laptop from about 2013 until present. When I wasn't on a network with IPv6 I started teredo (sudo service miredo start) and got IPv6 that way.
It was perfect. But then my disk crashed and I installed Ubuntu 15.10. Now it looks like traffic can't exit my laptop. After I get an IPv6 address with teredo I get "Network is unreachable".
IPv6 through router advertisements works well. But I can't use IPv6 from anywhere outside my home.
Any suggestions? I've tried reinstalling miredo.
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foo@bar:~$ traceroute6 www.kame.net
connect: Network is unreachable
foo@bar:~$ ifconfig teredo
teredo Link encap:UNSPEC HWaddr 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00
inet6 addr: 2001:0:53aa:64c:28c1:2168:94ec:4150/32 Scope:Global
inet6 addr: fe80::ffff:ffff:ffff/64 Scope:Link
UP POINTOPOINT RUNNING NOARP MULTICAST MTU:1280 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:3 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:500
RX bytes:0 (0.0 B) TX bytes:144 (144.0 B)
foo@bar:~$ route -6
Kernel IPv6 routing table
Destination Next Hop Flag Met Ref Use If
2001::/32 :: U 256 0 0 teredo
fe80::/64 :: U 256 0 0 wlp3s0
fe80::/64 :: U 256 0 0 teredo
::/0 :: !n -1 1 825 lo
::1/128 :: Un 0 4 14 lo
2001:0:53aa:64c:28c1:2168:94ec:4150/128 :: Un 0 1 0 lo
fe80::ffff:ffff:ffff/128 :: Un 0 1 0 lo
fe80::8e70:5aff:fec4:fe6c/128 :: Un 0 1 0 lo
ff00::/8 :: U 256 5 22 wlp3s0
ff00::/8 :: U 256 0 0 teredo
::/0 :: !n -1 1 825 lo
foo@bar:~$
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Seems like they fixed something with 16.04. Teredo is working again on my laptop after I upgraded it to the latest release.