07-20-2011 07:31 AM
Does someone here have some experience using DHCPv6 on a Windows 7 host when the DHCP server is on another subnet?
On my lab, "DHCPv6 Adertisement" are ignored on my Windows7 host, when the DHCP server is on another subnet. But:
- If I put my Windows7 host in the same subnet than my DHCPv6 server, everythings runs fine.
- If I use a DHCPv6 dibbler host (ie. linux host) in the other subnet, the DHCPv6 is working as expected.
I use a MLX with image 5100c for routing, and options like "ipv6 dhcp-relay-dest", "ipv6 nd managed-config-flag", "ipv6 nd prefix-advertisement" are configured as expected.
07-25-2011 05:09 PM
Not sure what DHCPv6 server you are using, but if Win 2008 then please look at this Kb
A DHCPv6 server that is running Windows Server 2008 may drop the DHCP relay-forwarded packets if these packets contain some unknown options
May or may not help.
03-26-2013 05:55 PM
Hi Vincent --
Here's a DHCPv6 summary I put together after boiling in pretty much the same oil you appear to have started out in (I'm still looking for a good relay solution -- I have 120 subnets to manage).
...and let me know if this needs any tweaking -- I was pretty thorough with my fact checking but another set of eyes is always welcome!
DHCPv6 doesn't work like DHCPv4.
The host gets its link-local address before doing anything else.
The host only uses DHCP to get a routable-scope address if told to by a router advertisement.
DHCPv6 servers listen on UDP port 547
DHCPv6 clients listen on UDP port 546
The whole conversation takes place in the local scope.
Per section 13 of RFC 3315 all client messages are sent to the following reserved multicast address:
Link local scope
A DHCPv6 Conversation:
DhcpV6 server link-local address: fe80::0011:22ff:fe33:5566
DHCPv6 client link-local address: fe80::aabb:ccff:fedd:eeff
DHCPv6 client sends Solicit: :546 ---> :547
DHCPv6 server sends Advertise: :546 <--- :547
DHCPv6 client sends Request: :546 ---> :547
DHCPv6 server sends Reply: :546 <--- :547
DHCPv6 across subnets:
No. link-local addresses are not routable.
Either the DHCPv6 server or a DHCPv6 Relay Agent has to be on the local link.
03-27-2013 06:00 AM
It seems that you answer to a very old topic. Issue was solved using 5.1.00e (january 2012?) and any newer version. Check the relase notes for "DEFECT000363769".
03-27-2013 09:46 AM
Thanks, Vincent -- I'm trying to figure out how to roll out IPv6 on nearly 150 subnets that are test environments and the absence of an IPv6 "IP Helper" function is really complicating the whole centralized address management issue. The info I posted helped clarify things here, I tghought maybe it might be useful to others as well. Thanks for the defect number -- I was about to go searching for it -- and if you know of anyone who may have made progress toward a working solution at any level (Brocade or whatever), I'd really appreciate a referral --