DHCPv6 client configuration

[vseta]

Hi all,

I looked into this for quite some time, found a couple of advices but they either didn't work or they suggested the necessity to install extra packages (which I don't believe is true).
So here I go: how do I make use of my computer's DUID?

My computer is a part of network that uses DHCP. The DHCPv6 uses DUID as unique identificator but my computer gets different IPv6 address than what it should (v4 works without problems).
First thing I set is in Network manager under the tab IPv6 field "Addresses" to "Automatic, DHCP only". However, often I got an IPv6 address that the DHCP server didn't issue. When I received address from the dynamic pool of DHCP, we got the DUID of my computer from the server and assigned it a "static" IPv6 address. Unfortunately, almost always I still get a "mysterious" generic IPv6 (starting fe80::) that obviously doesn't come from DHCP. Eventually I found a hint of DUID located at /var/lib/NetworkManager/dhclient6-MANYCHARS.lease, where the first line says default-duid "\000\004z?...";. When translated to hexadecimal, it corresponds to what the DHCP server is set to use. The DHCP client is configured correctly and other computers do work, whether Windows, Mac or other Linux distros. Any ideas why it doesn't get the IPv6 from DHCP server?

PS: I would like to suggest adding the ability to get DUID from simple command like ifconfig and display it in the Network Manager too.

[vseta]

Well, in the end we've learned by analyzing the traffic that the trouble was caused by the client never asking for new address, instead asking for renewal of the old and invalid one (and had two settings saved for extra confusion, more on that later). So, after clearing the /var/lib/NetworkManager/dhclient6-MANYCHARS.lease from all the configuration except DUID, it requested and received the address it was supposed to get. Then IPv6 was still not working outside the local network (despite receiving an address with global scope) but switching Network Manager from "Automatic, DHCP only" to "Automatic" solved that (obtained a total of 3 global addresses). The Network Manager keeps duplicating the settings (lease 6 {...} part) over and over for whatever reason in that file but I don't care for now since it works. Although I hope it gets fixed eventually.