Dynamic DNS with Godaddy and Comcast prefix delegation



  • I'm using prefix delegation to get an IPv6 from Comcast. It doesn't actually change that often, but still to be strictly correct I would like to make use of pfSense's dynamic DNS capability and Godaddy's API (RFC2136?) to keep my domain name and the IPv6 address pointing to my Windows 10 Pro server behind pfSense.

    I had a friend set this up, but it doesn't seem to be working. I don't even know where to find this function in the GoDaddy web page, apparently it is a separate user/password for IPv6 and IPv4 dynamic DNS API.

    My domain name is not resolving to my server IPv6. The MX record points to my email hosted at a static IP in a server farm, BTW, I don't want to change that. But I do want to point web, FTP, media server and other services at my server behind pfSense. Any ideas?

    248dfaa1-7046-4883-a4a7-86247743dc06-image.png



  • It looks like I got the GoDaddy API working partially. The IPV4 address matches my WAN IP, but the IPv6 doesn't match my server behind pfSense which is 2601:646:xxxx:xxxx:xxxx:xx:xxxx:6a2e. What IPv6 is pfSense giving Godaddy, and how do I get the updated IPv6 to be that of my windows PC?
    f1b630f1-05b5-4f3c-82ad-1fb0bd57b063-image.png



  • You're looking in the wrong place.
    What you're looking for is
    Services - DHCP Server & RA - DHCPv6 Server

    In order for this to work you need to enable DHCPv6 server, enter a range plus enter the settings under: Dynamic DNS

    You will also need to enable DHCPv6 client for your machines. I have no idea if Windows 10 have a working DHCPv6 client implementation. As a matter of fact most operating systems handle this quite differently. Some even don't offer an DHCPv6 client at all like Android. Such a mess. :-/

    Edit:
    The net obstacle you will face will be the firewall rule. While the IP doesn't change it's all fine but once it does your old rule doesn't apply any more. I don't know how to fix this though. If pfSense does not have a solution for those scenarios I think they should implement one.



  • @pmisch I have already enabled DHCPv6 server, entered an IPv6 range of fd38 in the RA section. Windows 10 is getting an IPv6 address, both public and local:

    2601:646:xxxx:xxxx:xxxx:xx:xxxx:6a2e
    fd38:ce4:xxxx:x:xxxx:xx:xxxx:6a2e
    

    So the first IP is public IPv6 for the server PC behind pfSense, with the second being the local IP. This seems correct for prefix delegation.

    But it looks like pfSense dynamic DNS is not sending out the server PC IPv6 to GoDaddy. I'm not sure what it is sending out. I guess I would somehow need to tell it to send the server PC IPv6, unlike IPv4 where there is only one public IP, and NAT handles the rest. But I don't think the IPv6 that is sent to GoDaddy is even the IPv6 of pfSense, the dynamic DNS prefix being sent is 2001.

    And yes, I do understand the firewall issue if the IPv6 changes, even though this is won't happen often. I'll try and address that later, but first things first.



  • @lifespeed
    Have you configured the section Dynamic DNS within the DHCPv6 server section?
    That's exactly what you need. Every time a client gets an IPv6 address via DHCPv6 it will send the information via DNS Update as in RFC2136 to the DNS server, see screenshot.dynamic_dns.png



  • @pmisch said in Dynamic DNS with Godaddy and Comcast prefix delegation:

    @lifespeed
    Have you configured the section Dynamic DNS within the DHCPv6 server section?
    That's exactly what you need. Every time a client gets an IPv6 address via DHCPv6 it will send the information via DNS Update as in RFC2136 to the DNS server, see screenshot.

    I see. I think. I didn't realize there was a Dynamic DNS section within DHCPv6 server. So here is what I did for Godaddy in the Dynamic DNS services section (not DHCPv6 - confusing). The "@" in the hostname field I think is OK, as the API probably connects to domain name using the key?
    b022b9d0-b958-41f9-aa73-f87e5ea8286a-image.png

    So this is what I've entered into the Dynamic DNS section of DHCPv6 server. The IPv4 address is for Godaddy primary nameserver. I have no idea if this correct.

    4cc58bd8-5add-47d3-a7ab-29d3637d0a1c-image.png



  • @pmisch said in Dynamic DNS with Godaddy and Comcast prefix delegation:

    The net obstacle you will face will be the firewall rule. While the IP doesn't change it's all fine but once it does your old rule doesn't apply any more. I don't know how to fix this though. If pfSense does not have a solution for those scenarios I think they should implement one.

    I think the solution is there, firewall rules can be host agnostic, at least for IPv4. For IPv6 it is not working right now.

    If someone knows if and how to configure the DDNS Section in the DHCPv6 Server for cloudflare, please let me know.



  • The IPv6 for my domain still has the 2001 prefix instead of the 2601 prefix delegated from my Comcast WAN. Did I not specify Dynamic DNS service or DHCPv6 Dynamic DNS subsection correctly? I haven't rebooted the router since last night, is that required?

    It seems like I'm close, sure would like to get this working. It was one of the main reasons I switched to pfSense.

    Edit: Should DDNS client updates field by changed to deny so that "DHCP will do the update and the client should not". I'm not even sure what the client is, presumably I want pfSense DHCP server to update Godaddy Dynamic DNS API.



  • Any ideas? pfSense is updating the IPv4 to Godaddy correctly, but despite my (mis?) configuration of the DDNS Section in the DHCPv6 Server, the IPv6 address sent to GoDaddy Dynamic DNS API is wrong.


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