[TriLUG] IPv6 and OpenWRT

[Sean Alexandre via TriLUG]

Thanks! That got me reading about stateless and stateful autoconfig, 
etc, and things are working now.

It turns out my problem was I'd firewalled IPv6 on the machine that 
needed an IPv6 address. I fixed that, and now it's getting a global 
Internet address, and not a local address.

I should have mentioned this is for OpenWRT Chaos Calmer rc2. It runs a 
daemon called odhcp6c [1,2] that does both RA (stateless) and DHCPv6 
(stateful.) Both are enabled by default.

So this is pretty cool! My machine on my "LAN" is now on the Internet 
too. (I'm not sure I can still call it my LAN??) I've still got firewall 
rules that block access, but plan to open it up some. That's next...

[1] http://wiki.openwrt.org/doc/techref/odhcp6c
[2] https://github.com/sbyx/odhcp6c


On 07/14/2015 10:49 PM, Igor Partola via TriLUG wrote:
> Most likely your OpenWRT installation is lacking radvd and a DHCP server
> capable of handing out IPv6. It seems that OpenWRT is moving towards
> inclusion of wide-dhcpv6-server by default, and latest builds don't have a
> compatible radvd package at all, so you might as well go with that now.
> Practically, there is no difference that you'll notice. Here's what I'd do:
>
> First, install wide-dhcpv6-server:
> http://wiki.openwrt.org/doc/howto/ipv6#wide-dhcpv6-server. Note that this
> will replace your normal DHCP server.
>
> Second, see if your machine called moose gets an address. If not, make sure
> the ipv6 kernel module is loaded (lsmod | grep ipv6). If not, update your
> kernel.
>
> Lastly, ensure you have firewall rules set up on OpenWRT. Personally, I
> allow ICMPv6 and port 22, and block everything else by default. In addition
> to that, I white-list some machines to handle their own firewalls such that
> I don't always have to go to the router to open a new port on one of the
> servers I run at home.
>
> Igor
>
> P.S.: it's best to use the ip (8) command to view these addresses (for
> example `ip addr`). It will tell you the type of address it is. For
> example, it would tell you that the fe80 address is "link local".
>