DHCPv6 leases going out, but not appearing in lease status [solved]



  • Trying to get IPv6 set up.  It mostly works, but is approaching more frustrating than its worth.

    One of the smaller – and thus, easier to solve, I had expected -- problems is trying to get static IPv6 mappings managed through DHCPv6.  (IPv4 leases have been working all along, and those static mappings are fine.)  The recommended approach is to let a normal dynamic address go out, and then once you have the DUID in the system, just add a static mapping from there.  Which worked fine for v4, and I expected to do the same thing for v6.

    Set up all the DHCPv6 bits, turned it on, and client started getting v6 addresses which were very obviously from the dynamic pool, all good.  (Assigned from the high end of the pool first, apparently, but still in the dynamic range.)  So I go to the Status -> DHCPv6 Leases page, and... there's nothing there.  Doesn't matter if I click the "show all configured" versus "active/static only", the table is just empty.

    Double-checked the Services -> DHCPv6 Server & RA -> Router Advertisements tab, and it's been on Managed the whole time.  I don't see how SLAAC could be involved, since the clients are getting addressed that are quite clearly out of the DHCP pool, but the DHCP server isn't showing that they were issued.

    So I don't know why this isn't working.



  • Hi,

    At the moment I have a pull request in github addressing the issues of the leases not showing up on the Status DHCPv6 Leases page:
    https://github.com/pfsense/pfsense/pull/3892

    If accepted this fix is likely to enter pfSense v. 2.4.3.

    I shall not rule out that something else could be wrong in your specific setup.
    Are you able to see the DHCPv6 leases in the menu of Diagnostics under the menu item NDP Table?
    If yes, then it is likely the fix in github fixes it.
    If no, maybe your configuration is not right. In that case you might want to share details about your interface setup, DHCPv6 Server and
    Router Advertisements setup.



  • @al:

    If accepted this fix is likely to enter pfSense v. 2.4.3.

    Excellent!  I'm running 2.4.2 so moving to .3 is totally an okay solution for me.

    I shall not rule out that something else could be wrong in your specific setup.
    Are you able to see the DHCPv6 leases in the menu of Diagnostics under the menu item NDP Table?

    I can see the dynamic lease that I was expecting to see, yes.  So it's probably due to the parser problem that your patch fixes.  Since it's a small network, I can get on each client and find out their DUID, and create the static mappings manually.

    I don't see any other DHCPv6 leases at all, though; neither dynamic nor statically mapping.  The rest of the NDP table, other than the router itself, are just the link-local addresses.  (So they're… not even asking for an address?  I would expect the Android phones to just languish in IPv4 until I get around to turning on SLAAC, but the laptops ought to be sending v6 solicitation packets... unless Windows 10 gets that wrong too...  They all seem to be making use of IPv6 even without the DHCPv6 leases, so this approach to a more thorough control of the local network is clearly incomplete.)

    Sorry, rambling aloud now.  Going to call the problem solved, and then turn off the dual stack until I can figure out a better way to do this.  Maybe use only ULAs combined with prefix translation, if that's even supposed to work with a tunnel provider on the outside...  I need more sleep.

    Thank you for your help, al!


 

© Copyright 2002 - 2018 Rubicon Communications, LLC | Privacy Policy