What options do I have if I need a router which can

  • Run a DHCPv6 client on its WAN port to request a delegated prefix (in the range /48 to /60).
  • Run a DHCPv6 server on the LAN and hand out subnets of the prefix it received from the WAN (sub-delegations in the range /52 to /62).

Other nice to have features which are not strict requirements:

  • Can forward small packets at 1Gbit/s wirespeed on all ports
  • Multiple LAN ports that can be configured as separate IP segments
  • Can provide the CLAT side of 464XLAT in order to support legacy devices connected to the LAN (as described in RFC 6877 section 6.5)
  • Can advertise its own DNS cache as primary DNS server and DNS servers advertised from the WAN as fallback.
  • OpenWrt can do prefix delegation, since Barrier Breaker. Not to mention almost everything else on the list, like DNS, 464XLAT and separate VLANs for each Ethernet port. But it's firmware that runs on a variety of routers, not all of which will meet your 1Gbps wire speed requirement. In particular, very few will NAT or firewall at that speed. Feb 4, 2018 at 2:00
  • @MichaelHampton Neither the 1Gbps nor the NAT capability are hard requirements. If it can do both separately but cannot do NAT at 1Gbps it would still be a very nice answer. NAT at 1Gbps is not something I expect to see. As for firewall what I'd really like to see is that it can do stateless firewalling of TCP (for performance and scalability) and stateful firewalling of everything else. But that sort of requirement felt too specific to include in my question.
    – kasperd
    Feb 4, 2018 at 12:06

2 Answers 2


I have done hierarchical prefix delegation using the AVM Fritz!Box routers.


Mikrotik Hex or any of their products based on RouterOS (most routers)

https://wiki.mikrotik.com/wiki/Manual:IPv6/DHCP_Client - look at the pool-name and pool-prerix-length parameters.

As for your bonus requirements:

  • 1 Gbit might need something more expensive
  • LAN - It is present
  • CLAT - I have no idea
  • DHCP cache - It is present
  • None of the examples on that page shows any recursive setups though. It shows that it can act as either a DHCPv6 client or a DHCPv6 server. Would be nice if it explicitly showed an example where the router acted as both.
    – kasperd
    Aug 3, 2018 at 20:34
  • @kasperd look at the parameters pool-name and pool-prefix-length.
    – jaskij
    Aug 4, 2018 at 10:38

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