The question asked below is based on the specific implementations of the Os not the RFC.

Looking on a way to be able to assign a fixed ip address to a host, before it boots I found that Centos 6 works fine with no modifications and Windows 7 does not work at all.

As defined in enter link description here exists 3 valid ways of generate a DUID:

  1        Link-layer address plus time
  2        Vendor-assigned unique ID based on Enterprise Number
  3        Link-layer address

Looking at the centos, that works fine, I can see the following autogenerated DUID:

option dhcp6.client-id 0:1:0:1:19:60:25:f1:52:54:0:6b:b9:9e;

and the MAC address for this host is:

ifconfig eth1 | grep HWaddr
eth1      Link encap:Ethernet  HWaddr 52:54:00:6B:B9:9E  

As you can see, the DUID containts the MAC address. I can assign a fixed ip address to this host by including an entry on my dhcp server similar to:

host vm {
    hardware ethernet 52:54:00:6B:B9:9E;
    fixed-address6 2001:db8:0:1::200;
    if packet(0,1) = 1 { log(debug,"VM Request match!"); }
}

And the Centos 6 gets his ip. On the windows side, I faced a common problem explained on this other link enter link description here

As summary, Win7 uses the option 2 of the DUID generation or a variation of this one. On the link explains how to move it to a llt (link layer + time) but is not working fine. If I modify the DUID to one that looks like the one generated on Centos (but with the right MAC) it works as expected.

Question 1 How Can I change the DUID generation for Windows 7 to be based on MAC as Centos 6 does?

Thanks