I'm trying to use a Raspberry Pi to set up as a tunnel broker via tunnelbroker.net.

I have a simple set up that looks roughly like this:

Verizon ISP Switch/IPv4 Router
        |----- Raspberry Pi - set as DMZ Host
        |----- DevLaptop

The tunnel is set up properly via the Raspberry Pi since I'm able to ping6 ipv6.google.com I'm also able to ping the IPv6 gateway from the Raspberry Pi

I'm trying to get DevLaptop to access IPv6 networks as well via radvd on the Raspberry PI.

Even though DevLaptop is able to obtain an IPv6 address I'm not able to ping6 ipv6.google.com. I get the error message unknown host

First, here's the config on the Raspberry device.

ip -6 route show

::/96 dev sit0  proto kernel  metric 256 
2001:470:1f0e:6b7::1 dev he-ipv6  metric 1024 
2001:470:1f0e:6b7::/64 dev he-ipv6  proto kernel  metric 256 
2001:470:1f0f:6b7::/64 dev eth0  proto kernel  metric 256 
fe80::/64 dev he-ipv6  proto kernel  metric 256 
fe80::/64 dev eth0  proto kernel  metric 256 
default via 2001:470:1f0e:6b7::1 dev he-ipv6  metric 1024

RPi config

iface default inet dhcp

iface eth0 inet static

auto he-ipv6
iface he-ipv6 inet6 v4tunnel
        address 2001:470:1f0e:6b7::2
        netmask 64
        ttl 255
        gateway 2001:470:1f0e:6b7::1

        #notice :1f0f: and not :1f0e:
        up ip addr add 2001:470:1f0f:6b7::1/64 dev eth0 


interface eth0
    AdvSendAdvert on;
    prefix 2001:470:1f0f:6b7::/64
        AdvOnLink on;
        AdvAutonomous on;

Here's DevLaptop's obtained ipv6 address.


eth1      Link encap:Ethernet  HWaddr d8:eb:97:b3:05:c9  
          inet6 addr: 2001:470:1f0f:6b7:daeb:97ff:feb3:5c9/64 Scope:Global
          inet6 addr: fe80::daeb:97ff:feb3:5c9/64 Scope:Link
          inet6 addr: 2001:470:1f0f:6b7:1ceb:5449:6d4:efb6/64 Scope:Global
          RX packets:155 errors:0 dropped:0 overruns:0 frame:0
          TX packets:151 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:24409 (24.4 KB)  TX bytes:32980 (32.9 KB)

$ ip -6 route show

2001:470:1f0f:6b7::/64 dev eth1  proto kernel  metric 256  expires 86348sec
fe80::/64 dev eth1  proto kernel  metric 256 
default via fe80::ba27:ebff:fed5:b552 dev eth1  proto static  metric 1 
default via fe80::ba27:ebff:fed5:b552 dev eth1  proto ra  metric 1024  expires 1748sec

The only thing I'm able to do from DevLaptop is ping and get a response from the Raspberry with ping6 2001:470:1f0f:6b7::1

I wanted to do this as a weekend project to start getting familiar with IPv6 networks. Can someone point me in the right direction as to why DevLaptop is unable to reach other IPv6 networks? I was under the impression IPv6 devices would auto configure themselves after receiving a router advertisement. Is there something I'm missing?

Bonus question: My ipv6 tunnel broker is also offering a different /48 address besides the /64 address I listed above. What is the purpose of using a /48 network address versus /64?

migrated from serverfault.com Mar 1 '15 at 13:19

This question came from our site for system and network administrators.


You can't put the same subnet on both the tunnel and your local LAN. Tunnelbroker.net will have given you a separate /64 for your LAN and you can even request a whole /48 if you have multiple LANs. Use those and it should work.

  • You were right, thanks. The broker endpoint was 2001:470:1f0e while subnet for my LAN was 2001:470:1f0f. I had simply used the wrong one like you said. However, is there a way to refresh the interface? When I changed the routing advertisement the laptop had the IP from the correct subnet immediately but I wasn't able to connect to the internet after like 5 minutes. – Tek Mar 1 '15 at 11:18
  • Yes, radvd doesn't work without it. – Tek Mar 1 '15 at 11:20
  • Please edit your question and put in the right addresses. Can you also show your IPv6 routing table? And if you've configured it your ip6tables. – Sander Steffann Mar 1 '15 at 11:22
  • I've updated my config above. I have not configured any ip6tables yet. – Tek Mar 1 '15 at 11:35
  • Sorry, I meant the routing table of your RPi ☺ – Sander Steffann Mar 1 '15 at 11:39

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