0

I'm playing with Windows 2012 DHCP server for IPv6. As with IPv4, the client network interfaces can be configured to either obtain an IPv6 address automatically, or use a statically configured address.

However, what I observe is that even for those hosts where I configured a static IPv6 address, they additionally acquire a DHCP address. This is even the case for the DHCP server itself!

How come?

1

The automatic address is from stateless address configuration. If you want to use stateful (with static addresses) configure your router to turn off the autonomous flag and turn on the manual flag. Some people say to turn on the other flag, literally called 'other' flag. I don't know what this does but setting the manual flag and autonomous flags work for us.

If you run get-netipaddress in powershell it will tell you the origin of the addresses.

This question gets asked a lot and seems to be a common misunderstanding of how IPv6 works.

What is really crazy is when the manual flag and autonomous flags are both on, then the server has about 4 addresses; DHCP assigned stateful, DHCP stateless, link, and static.

7
  • Yes, most of the time I think IPv6 is just a more-bits version of IPv4 :) get-netipaddress tells me that the origin of th addresses is dhcp, which I alreday knew. - Not sure what my router has to do with it, it does not have IPv6 activated (yet) May 21 '15 at 18:13
  • Upon second thought I think the real question behind my question is: Would it be safe / useful /best practice to simply let even the DHCP server itself acquire its address solely voa DHCP (so from itself) without there being a bootstrapping conundrum ... ? May 21 '15 at 18:24
  • We do not for the same reason we assign a number to the gateway despite the gateway only using local link. If something happens to DHCP/DNS we want the server to still be online, something that can't be assured with DHCP stateless or autonomous addressing (as in DNS doesn't work so we can enter the IPv6 address into RDP). It also allows the DNS announcement from DHCP to be accurate, which is most likely the important thing.
    – UpTide
    May 22 '15 at 15:26
  • What flags do you have turned on?
    – UpTide
    May 22 '15 at 15:32
  • 1
    The whole DHCP idea has changed with IPv6. The network is configured to either be stateful, stateless with DHCP, or stateless without DHCP. The flags that control the network 'state' if you will, are on the router; Windows has about 0% to do with the 'state' in a normal setup. There are ways to manually make Windows advertise these but it isn't the way it should be. With IPv6 you must have a router along with a DHCP server to make a network.
    – UpTide
    May 22 '15 at 18:10

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.