Hurricane Electric 6in4 IPv6 "Error: Network device is not present"

I have been trying to get 6in4 tunnelling working and the tunnel won't come up, and doesn't show up when I run ifconfig or ip tunnel and in luci it just says "Error: Network device is not present"

Relevant portion of /etc/config/network

config interface 'henet'
        option proto '6in4'
        option peeraddr ''
        option ip6addr '2001:470:1c:ef::2/64'
        option ip6prefix '2001:470:1d:ef::/64'
        option tunnelid '------'
        option username '------'
        option updatekey '------'
        option mtu '1452'

I haven't been able to find anyone else having this issue.

I think you may want to lower the mtu to 1424, add a ttl setting of 64 and use your routed /48 prefix for ip6prefix, instead of the /64 used for the tunnel.

This works for me:

config interface 'wan6'
        option proto '6in4'
        option ifname '@wan'
        option peeraddr ''
        option tunnelid 'xxxxxxxx'
        option username 'xxxxxxxx'
        option password 'xxxxxxxx'
        option ip6prefix '2001:470:xxxx::/48'
        option ip6addr '2001:470:xxxx:xxxx::2'
        option mtu '1472'

Thank you so much for this thread! I've had my tunnel up and running with no obvious issues for years, but was recently trying to get a remote Plex media server to stream video over IPv6. IPv4 was fine but it buffered constantly over IPv6. I assumed it was my ISP (Virgin Media in the UK) applying traffic shaping to the 6in4 traffic but seeing this thread made me check the MTU on the 6in4 interface. It defaults to 1280! Changing it to 1480 (I'm on a cable modem in modem mode) results in great quality streaming over IPv6 :+1:t2::+1:t2::+1:t2:

(I'm so annoyed with myself for not thinking to check this before :roll_eyes:)

The /48 is optional, by default they provide a /64 which is one bit different. In his case it is correct (:1c: and :1d:)

The MTU should be set under the advanced tab of the tunnel details (is 1480 by default)

Anything in the logs when you try to bring up the interface?

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Nope, I looked, trying to figure out why it was failing. It's not even getting as far as connectivity problems, the tunnel doesn't exist at all.

lsmod | grep sit
root@OpenWrt:~# lsmod | grep sit
ip_tunnel              10656  1 sit
sit                    12864  0 
tunnel4                 1984  1 sit

Have you done -

opkg update
opkg install 6in4 luci-proto-ipv6


root@OpenWrt:~# opkg install 6in4 luci-proto-ipv6
Package 6in4 (25-1) installed in root is up to date.
Package luci-proto-ipv6 (git-19.051.55698-76cf653-1) installed in root is up to date.

Hummm...I have a slightly different ifname whatsoever.

config interface 'henet'                          
        option proto '6in4'                      
        option peeraddr ''             
        option ip6addr '2001:4xxx:xxxx:xxxx:xxxx:2/64'     
        option ip6prefix '2001:xxxx:xxxx::/48'                                   
        option mtu '1480'
        # I use DDNS for the following now - but they did work for me
        option tunnelid 'xxxxxxxx'
        option username 'xxxxxxxx'
        option password 'xxxxxxxx'

You can also get come config hints from the Example Configurations screen on the Tunnebroker website - that's how I configured my first OpenWrt for IPv6:


If you need LAN configs too, let me know.

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If I recall correctly, this was recommended somewhere sometime ago, as a means to tie the 6in4 connection to the WAN interface, so the former would restart in case the later restarted.

Also, I get my internet connection from a PPPoE link, with a MTU of 1492 bytes, so the MTU on the 6in4 connection cannot be larger than 1472 bytes for me.

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I believe it should be option tunlink.

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Thanks, I will try that.

[Slightly OT] I recently (late January 2019) updated the 6in4 Hurricane Electric tunnel docs at Setting up an IPv6 Tunnel with LuCI, partly to get out of the business of editing config files.

I haven't done a diff against your configs and my instructions, but if you find any errors in my instructions, I'd be delighted to fix them.

Update: That page also has links to script that automatically reconfigures a tunnel - I found it useful when I was re-flashing my router on a weekly basis while testing firmware.

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