DHCPv6 and specifying IP exlcustions for a default /64 scope

Copper Contributor



I am currently in the process of setting up dhcpv6 on my AD server and I noticed that when you specify the dhcpv6 scope you are restricted to only setting a /64 prefix.  (This is way more IP's then I need for the dhcpv6 scope)  I want to only hand out a /113 specific range.


I noticed the only way to do this is to exclude a hole lot of IP's in the /64.


How do I come up with the exclusion list so that I am only handing out that specific /113 prefix that I have?


Or would it just be better to use unique /64s for each vlan?




vlan1 - 2001:1900:3000:4::0/64

vlan2 - 2001:1900:3000:5::0/64

vlan3 - 2001:1900:3000:6::0/64


I look forward to hearing peoples thoughts


Thanks in advance

2 Replies
You have to use a pair of exclusion ranges per scope. I'm sure if you've looked up to the IPv4 section, you'd have noticed "inclusion ranges". I submitted a request to have Microsoft include it back in 2010 but they declined.

Let's say you're trying to dole out 2001:1900:3000:4:abcd:dead:beef:0/113

Youd' set:
Exclusion 1 = 2001:1900:3000:4:: to 2001:1900:3000:4:abcd:dead:beef:0
Exclusion 2 = 2001:1900:3000:4:abcd:dead:beef:ffff to 2001:1900:3000:4:ffff:ffff:ffff:ffff

To be exact, it would technically be:
Exclusion 1 = 2001:1900:3000:4:: to 2001:1900:3000:4:abcd:dead:beee:ffff
Exclusion 2 = 2001:1900:3000:4:abcd:dead:bef0:0 to 2001:1900:3000:4:ffff:ffff:ffff:ffff
to include the first and last address in the range (if you really wanted the scope to start at the 0th address) but normally you don't result in "beee:ffff" it just makes doing the math harder.