Netgate Discussion Forum
    • Categories
    • Recent
    • Tags
    • Popular
    • Users
    • Search
    • Register
    • Login

    DHCP Relay Advice

    DHCP and DNS
    2
    7
    3.4k
    Loading More Posts
    • Oldest to Newest
    • Newest to Oldest
    • Most Votes
    Reply
    • Reply as topic
    Log in to reply
    This topic has been deleted. Only users with topic management privileges can see it.
    • S
      stephen
      last edited by

      Hello,

      Trying to setup a simple pfsense box.  Currently has 3 interfaces, wan, lan, opt1.

      OPT1 goes to a Windows server which will be hosting active directory, dhcp, dns… all network services basically.  LAN goes to a switch, which then goes out to all the other computers.  T1 line is connected to WAN.

      The ideal setup would be having the Windows server on OPT1 and have the LAN pass DHCP requests onto the OPT1 interface.  So far this has deemed unsuccessful.

      Current setup:
      WAN is a static IP to the Internet.
      LAN 192.168.1.1
      OPT1 192.168.2.1

      Rules are setup to allow any/all traffic from OPT1 and LAN.  Additionally I have temporarily setup a PPTP VPN on 192.168.1.2 (192.168.1.16/28), this is just so I can access everything remotely without having to open a bunch of ports for now.

      The Windows server has an IP address of 192.168.2.2, and currently being forwarded DHCP requests from the LAN.  However clients are unable to obtain an IP.  The network on the Windows server is 10.0.100.1 (though this shouldn't matter, right?).

      Can you please advise me if I'm doing this correctly?  At the moment no clients are able to connect to the network.

      Stephen Crawford

      1 Reply Last reply Reply Quote 0
      • C
        cmb
        last edited by

        As long as you have multiple scopes with the appropriate IP ranges on the Windows server, putting in its IP as the relay will do just what you're looking for. That's how I do DHCP on several networks.

        1 Reply Last reply Reply Quote 0
        • S
          stephen
          last edited by

          Ok, so basically I would need a scope for 192.168.2.1?  I suppose it would be easier to change my OPT1 interface to 10.0.100.1 since thats the scope we already have setup.  Sound right?

          Stephen Crawford

          1 Reply Last reply Reply Quote 0
          • C
            cmb
            last edited by

            You'll need one scope per interface, each interface has to have its own subnet. Then the DHCP relay tags the forward with the subnet of that interface, and Windows knows which scope to serve from there.

            1 Reply Last reply Reply Quote 0
            • S
              stephen
              last edited by

              Ah yes, worked perfectly after wrestling with it.  Changed the LAN interface to match the IP address of scope on Windows, after a little more config of scope options it was working like a charm.

              My PPTP VPN quit working though, any idea how I could make that work again with this configuration? Or should I just forget about it..

              Stephen Crawford

              1 Reply Last reply Reply Quote 0
              • C
                cmb
                last edited by

                I can't think of anything to do with DHCP relay that would affect PPTP. Start a new thread describing that issue.

                1 Reply Last reply Reply Quote 0
                • S
                  stephen
                  last edited by

                  The VPN randomly started working.  I'm not gong to ask any questions and just go along with it  ;D

                  Thanks again for all your help.

                  Stephen Crawford

                  1 Reply Last reply Reply Quote 0
                  • First post
                    Last post
                  Copyright 2025 Rubicon Communications LLC (Netgate). All rights reserved.