IPv6 + DHCP-PD /56 Allocations

RouterOS General
1

Hello all. I am swapping a pfSense appliance with a Mikrotik Hex S. Everything has gone smoothly except for one item relating to IPv6. My provider (US Spectrum/TWC) provides a /56 prefix through DHCPv6-PD. I can obtain the prefix delegation from Spectrum just fine and it shows up in the Pools tab. I have multiple interfaces/vlans I need to assign addressing to. I can assign the first address/network to one of the interfaces and it assigns a working /64. However trying to assign the second interface a similar setup gives the error “address pool error: Pool SpectrumV6 exhausted- no more addresses left! (14)”. When I look at the pools tab, the entire /56 is marked in “Used Prefixes” which doesn’t seem to be right. Do I need to do something further to allow more allocations from the pool?

I’ve looked through the forum to find this particular condition but haven’t seem to found it. The only discussion I stumbled across that was describing a similar question on /56 PDs just had a “it just worked for me” closure note.

The system is running Stable 6.48.1.

2

I think you should set prefix-length=64 to your pool, so that assignments are in 64 bit pieces

3

Well, that’s part of what I’m asking. Since the pool is dynamic, it can’t be edited directly. Is there some other setting for that elsewhere I’m missing on the system or in the documentation?

4

OH… I think I just realized what you meant. Are you talking about in the DHCP Client section? I was thinking that “Pool Prefix Length” was referring to the PD hint as well and they needed to match. But I think I see what you mean now and will try it.

5

Yep, that was my error. I had Pool Prefix set to /56 the same as the Delegation Hint. I just glossed right over that. Thanks!