@johnpoz said...
I don't think so. Your interface should have a /64 on it... What you delegate would be under the delegation pool range.
Your downstream device for example would grab an IP out of the /64 range, and then request a delegation for networks for it to use and hand out behind it.. Its wan would have an IP out of the /64, and it would get a say a /56 that it would use for delegation for stuff behind it.
Meaning, what it delegates would not overlap with what it has itself... which is not allowed.
Try it for yourself; I just did:
Whatever the size you provide to the interface...
Is the TOTAL range available to that interface, including all delegated ranges.
If /64, then only /64 or smaller is available for any use under that interface.
By using /56:
I can set a /64 range for DHCPv6 of the interface
AND I can allocate a lot of space for delegation (say, /60)
In practical terms...
if /48 is aaaa:bbbb:cccc::
and /56 for an interface is aaaa:bbbb:cccc:9900::
Then for that ifce DHCPv6, it has ...9900 through ...99ff available.
So I can use ...9900 for my own /64 dhcp
and ...9910-991f would be a nice /60 delegation
etc.
(BTW, I've learned to allocate from the left in a quad (abcd)... because :1: means :0001: not :1000: ... that took me a few moments to realize!)