DHCPv6 across VLANs

  • Hi all,

    I've a challenge I've been struggling to overcome with little success to this point. I have just turned up IPv6 and received a /57 from my provider. Both the WAN and LAN interfaces are able to obtain addressing from the ISP. I have configured prefix delegation and router advertisements for the LAN interface (/64) and it works great in LAN clients obtain automatic addressing from the pfSense DHCPv6 server. RA is set for Assisted and my subnets defined as 2605:6001:e70e:2200::/64. The LAN interface itself set to track interface for WAN.

    The problem is that none of the clients in my defined VLANs are receiving DHCPv6 addressing. I do understand that VLANs are individual broadcast domains and that these broadcasts do not transit to other networks by design. However, without a DHCPv6 Relay or the ability to assign a static address within the scope (/57) how do I get an IPv6 address for each of the networks and pass DHCPv6 to and from the VLANs to this single DHCPv server?

    I am sure I am missing some piece of the informaiton pie that I am not aware of, but this is my first foray in to IPv6.

  • LAYER 8 Global Moderator

    /57 seems like an odd prefix

    Normally you would set your other lan interfaces/vlans to just a different prefix in their track.. So for example use prefix ID 0 on your lan, you would use prefix ID 1, ID 2, etc for your other interfaces.

    Did they assign you a static /57??  If so you could always just create static /64's on your other interfaces vs using track.

  • /57 seems like an odd prefix

    My ISP will soon be letting customers choose any prefix, from /64 to /56.

  • @johnpoz:

    So for example use prefix ID 0 on your lan, you would use prefix ID 1, ID 2, etc for your other interfaces.

    EXACTLY, the help I needed. Thank you John!

    Yes a /57 seemed really odd to me as well, even though this is my first IPv6 net. I removed all configuration and proceeded with the prefix ID's and rebooted. Now I've received a /64 for each VLAN and am able to configure DHCPv6 for each VLAN.

    Time to dig in to TCP/IP bible and learn each setting today. I knew I was missing something simple.

  • LAYER 8 Global Moderator

    if you want to learn some ipv6 stuff, head over to hurricane electric and take their certification test.  Its a learning progressive thing, some things you have to do like run web server, email server on your ipv6, etc.  Once you get to sage you can get a free t-shirt ;)


    I love sporting my sage shirt at techie gatherings.

  • Another good source of info is "IPv6 Essentials".

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