OpenWRT version: 18.06.1 r7258-5eb055306f
Router: Linksys WRT1900ACS
I'm trying to figure out why doesn't my router doesn't assign ipv6 addresses to my LAN.
My guess is that it doesn't support DHCPv6-Prefix Delegation. The hint is that despite the WAN6 configuration looks like the follwing:
config interface 'wan6' option ifname 'eth1.2' option proto 'dhcpv6' option reqaddress 'try' option reqprefix '56'
The resulting ipv6 on WAN6 interface is /64. If reqaddress is set to 'force' for any reqprefix it fails to get an IPv6 address.
No problem here. Just nuances of my ISP. To fix this, I go to LUCI->Lan->IPV6 Settings and then set everything to relay in order to everything start working. However, it didn't.
This configuration reflects in /etc/config/dhcp as such:
config dhcp 'lan' option interface 'lan' option start '100' option limit '150' option leasetime '12h' NEW: option dhcpv6 'relay' NEW: option ra 'relay'
However this didn't work.
OpenWRT has a few documentation on this I had also to set the following.
config dhcp 'wan' option interface 'wan' option ignore '1' NEW: option ra 'relay' NEW: option dhcpv6 'relay' NEW: option ndp 'relay' NEW: option master '1'
And after a reboot LAN clients have IPv6 connectivity.
A few questions raise from this:
where are 'ra', 'dhcpv6 dhcp wan settings settings in LUCI?
Is it a bug that "wan" section needs configuration (post #5) instead of "wan6" as documentation suggests?
What does "master" option does?
I also noticed that Luci -> Network -> DHCP and DNS aren't aware of LAN IPv6 clients.
Am I firewalled or are my IPv6 LAN clients exposed in the internet?
How do I open a port for a LAN client? (e.g. ssh)
According to the same thread (post #6 of the same thread):
For prefix delegation to work downstream, there should be several /64 prefixes available (at least two, so that the Openwrt router would keep one for itself and its WAN side (=modem side) and assign the other for its LAN). When the Openwrt router gets assigned a only single /64, there is nothing to delegate further for its own LAN side.
Actually, your case might be for interest for the odhcpd developer (sbyx / CyrusFF), as the automatic switch from PD mode to relaying did not work. (Wiki gives you the impression that it should work.)
How do I check how many /64 did my ISP router attributed to OpenWRT router?
Is there any way to debug if Prefix Delegation is available?
This is not out of the box configuration. Should any of this be reported as a bug?