I noticed that my DHCP settings are missing a column compared to yours. In your picture, the second column from the right is the device's DUID?
Maybe I am missing a package or missing updates.
Maybe I can adjust the config file directly, or use the command to set it.
There are multiple ways for clients to get IPv6 addresses, if your client isn't using DHCPv6 then none of the DHCPv6 settings will have any effect.
some of the possibilities are:
SLAAC with MAC based address
Privacy addresses
Stable Privacy addresses
DHCPv6
Statically configured addresses
Many clients use more than one strategy.
A good solution for your use case might be to configure a static address on your client, and then put the address in the /etc/hosts file so that DNSmasq knows about, and just use the hostname.
Thanks, I flashed the latest firmware for openwrt
OpenWrt 18.06.2 r7676-cddd7b4c77 / LuCI openwrt-18.06 branch (git-19.020.41695-6f6641d) (it does not have a wireless driver, but does not affect the other)
And found the missing configuration.
I set it up.
[del]However, it is still not possible to set an IPv6 address.[/del]
After a long reboot, it worked, I saw the IP address I wanted.
Can't actually be configured on the server, even with DHCPv6? Because ipv4 can, so I guess ipv6 can also.
I thought it would be more difficult to configure on the client.
In any case I've always assigned a static IP on the client. Perhaps I misunderstand what you desire to do. It seems you want to RESERVE A DHCP-issued IP in the DHCP server, NOT assign a static address to a client.
It depends on the client, but you can have multiple ipv6 addresses on one interface. As long as the router is sending RA, you can have the SLAAC address. If there is DHCPv6 you can also run a dhcp6c on the client. And of course you can assign a static IP by yourself.