The Windows Server DHCP Service has the ability to add predefined options for IPv4 and IPv6 by right clicking on the protocol and selecting "Set Predefined Options"
On IPv4 they work in just the same way that they worked on 2008 and 2003, one can set options to have a specific value, and one can add new options.
On IPv6, it appears that one can add new options (in this case option 59 for IPv6 PXE), but the options does not show and are not used.
The DHCP server has been configured with stateful DHCPv6 to provide recursive nameservers and a domain search list. WDS is not installed on the server.
In this instance I am trying to add option 59 to enable PXE on IPv6, and I am able to add the option via the GUI, but it does not show, if however I try to add option 59 again an error is shown "The given option identifier is already in use".
If the config is dumped to a file
netsh dhcp server dump > C:\temp\dhcpexport.txt
then the option (without any setting) is shown
Dhcp Server \\dhcp-1.domain.com v6 Add Optiondef 59 "BootURL" STRING 0 comment="IPv6 BootURL""
If the dump file is edited and the line extended with a Boot URL
Dhcp Server \\dhcp-1.domain.com v6 Add Optiondef 59 "BootURL" STRING 0 comment="IPv6 BootURL"tftp://tftp-1.domain.com/bootfile.bin"
then executed
netsh exec C:\temp\dhcpexport.txt
If the dump is created again, the edited part is still there, but it still does not show in the GUI.
Using Wireshark to capture all traffic to and from the client via a monitor port, I can see the initial request from the client for option 23 (recursive nameserver) and the response to the client, and then the second request for options 3, 59 and 60, but the response to the client only includes option 3.
I presume I am missing something basic, but I'm lost as to what it might be...
