DHCPv6 on pfSense is confusing me



  • All

    pfSense version: 2.3.3-RELEASE

    I am trying to enable DHCPv6 on an existing lab network. Using a provider allocated /48, subnetted further into /64s, I have enabled DHCPv6 on one of the subnets with 20-25 hosts, and all of the hosts configured for v6 with DHCPv6 are getting successfully getting addresses within the range allocated. So far so good.

    First issue: When I checked status/DHCPv6 leases, it shows leases being allocated, BUT only some of them (event after selecting "Show all configured leases".

    Second issue: I tried to force the issue by copying the DUID of on the leases in the list, and creating a static mapping for a specific v6 address. The host continues to get a dynamic address, so possibly the DUID as listed in DHCPv6 leases is a different format than the static mapping wants?

    Third issue: After I configured this single static mapping, this now became the ONLY lease listed under DHCPv6 leases. I removed it, and now have NOT DHCPv6 leases in the list….. and checking on several hosts, they all continue to obtain addressing from pfSense DHCPv6 in the proper range.

    Any ideas what's going on with DHCPv6?



  • Forgot to mention – RA is enabled in Managed mode on this DHCPv6 interface. Have also tried Assisted mode with the same results.



  • Normally, you should be using assisted.

    You said that your devices are getting addresses, but are you sure the addresses are from dhcp in the configured range? Even if you have dhcp, some devices won't use it, such as android devices. If there is a dhcp address, you should see a lease for it.

    Not sure what you mean by "copying the DUID". Each host must have a unique DUID.

    If you make a static mapping, there will not be a lease, because a lease isn't needed.

    It would help if you posted screen captures of Services DHCPv6 Server & RA LAN DHCPv6 Server and Status DHCPv6 Leases.

    Sometimes when you make changes, it helps to restart dhcp and release / renew the connection on the host.



  • All hosts use DHCPv6 (CentOS, Ubuntu)

    By static mapping, I dont mean static addressing, but static DHCP – allows dynamic updates to DHCP config scope (dns, ntp, tftp, etc) but effectively a static address per host. I should be able to allow DHCPv6 to dynamically allocate an address, then grab the Host DUID from the DHCPv6 list, and create the static mapping within DHCPv6 config.

    As I said, the issue is that addresses being allocated from this DHCPb6 server are not showing up in the DHCPv6 lease list.

    I will try a restart on the service, see if that changes anything -- if not that, will try reboot of pfSense.



  • I'm seeing this same issue. No leases show up in the dhcp6 lease list. I resorted to grabbing DUID's from the dhcp6's logs of assigned IP's.
    I've tried rebooting, and of course stopping and starting the DHCP service.

    I have DHCPv6 enabled only on my DMZ interface, not LAN or WLAN. Is that what's doing this? My DMZ is managed, the others are unmanaged.



  • I don't normally use static mappings for dhcpv6, but all of my hosts using dhcpv6 show up in the list of leases. If I ping the address, it goes online and the mac is displayed. If you use dhcpv6 without a static mapping, does that work?

    I created a static mapping on my pfsense 2.4 beta system and there seem to be some strange things. I'll try on my pfsense 2.3.3-p1 system and report back.



  • Even without static mappings, leases do appear in the DHCPv6 lease list, but not all of them….

    I can literally sit on a host, monitor the DHCPv6 renewal process to be successful, and look on the DHCPv6 lease list on pfSense, and the lease is not listed. I can ping6 the host without issue, but still does not show up in the list. Would like to get to static mappings, but need to resolve this issue first.



  • @dhockenberry:

    Even without static mappings, leases do appear in the DHCPv6 lease list, but not all of them….

    I can literally sit on a host, monitor the DHCPv6 renewal process to be successful, and look on the DHCPv6 lease list on pfSense, and the lease is not listed. I can ping6 the host without issue, but still does not show up in the list. Would like to get to static mappings, but need to resolve this issue first.

    Are the addresses for which the leases not showing up in the ndp table? Is there anything unusual about the host names? When you ping the host, does the host name appear with the domain appended? Check in /var/dhcpd/var/db/dhcpd6.leases to see if there is a lease but it's not being displayed. Are the addresses that you think are being allocated for leases in the range that you have configured? Try restarting dhcpd and see if that makes any difference.

    Regarding the static mappings, I'm going to look at this for a while. There seems to be some weird sh*t going on.



  • There are some problems creating ipv6 static mappings. I created a bug. https://redmine.pfsense.org/issues/7443

    BTW, I tested with 2.4 beta.



  • Thanks for the reference to https://redmine.pfsense.org/issues/7443

    I was able to get (at least) the DHCPv6 server to dynamically allocate and list addresses correctly, after a system restart  :)

    But static mapping is still not working. I went to the DHCPv6 log (cli, as I am not yet trusting the web interface on this info), and captured the DUID assignment to a known target, and tried to create a static mapping using this DUID – no joy.

    Based on the reference you posted, I imagine this will be fixed in some upcoming release -- will monitor the release notes :)



  • I submitted the bug against 2.4 beta. I haven't had a chance to try it on my 2.3.3-p1 system. The bug was assigned to a developer, so that's a good sign.

    So are you saying now that leases are being allocated and they are showing up on status / dhcpv6 leases?


  • Rebel Alliance Developer Netgate

    There is an issue with the leases being displayed as well: https://redmine.pfsense.org/issues/7413


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