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    DHCP on multiple interfaces

    Scheduled Pinned Locked Moved DHCP and DNS
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    • johnpozJ
      johnpoz LAYER 8 Global Moderator
      last edited by

      @ddanielpala said in DHCP on multiple interfaces:

      Other networks are wired. Not in DHCP

      Huh?? What does wired or not have to do with dhcp? Your saying those other networks are all assigned static on the devices? Why? How many devices?

      An intelligent man is sometimes forced to be drunk to spend time with his fools
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      • D
        danldn31
        last edited by

        Forget about other networks. What I am trying to achieve is to have two DHCP server on two different networks for clients to connect. Thanks.

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        • JKnottJ
          JKnott @danldn31
          last edited by

          @ddanielpala said in DHCP on multiple interfaces:

          What I am trying to achieve is to have two DHCP server on two different networks for clients to connect.

          You can configure a DHCP server on every interface.

          PfSense running on Qotom mini PC
          i5 CPU, 4 GB memory, 32 GB SSD & 4 Intel Gb Ethernet ports.
          UniFi AC-Lite access point

          I haven't lost my mind. It's around here...somewhere...

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          • johnpozJ
            johnpoz LAYER 8 Global Moderator
            last edited by johnpoz

            Yeah you could have 100's, shoot prob 1000s - depending on the umph of your hardware of networks and dhcp running on all of them.. I'm just a bit confused to how that is even a question.. Pfsense would be pretty freaking crappy if you could only run dhcpd on 1 network at a time ;) hehehe

            So yeah, you can run multiple networks with dhcpd on any or all of them if you want.. Just click the little enable dhcp check box on the interface in the dhcp server section.

            What you can not do, and people complain about it is run dhcpd and a dhcp relay.. You can either relay or be dhcp server.. You can not do both things at the same time, even on different networks.

            An intelligent man is sometimes forced to be drunk to spend time with his fools
            If you get confused: Listen to the Music Play
            Please don't Chat/PM me for help, unless mod related
            SG-4860 24.11 | Lab VMs 2.8, 24.11

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            • D
              danldn31 @johnpoz
              last edited by

              @johnpoz Yes, so just thinking, if i have two such dhcp services running, will a personal device that connects to the wifi network get IP from second dhcp service that running on second interface. What changes need to be done to make that work.

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              • johnpozJ
                johnpoz LAYER 8 Global Moderator
                last edited by

                Huh... You said these would be different networks..

                Please do not trying and run multiple layer 3 networks on the same Layer 2 network... That is just borked and cause you all kinds of issues.. Especially if any of these devices need to talk to each other..

                If this is a single layer 2 network.. Then you NEED to change its ip range so you can increase network size to be appropriate for number of devices.. /23 or /22 - I really wouldn't put more than say a /22 on the same network.. Especially if they are chatty little window boxes that love to send out craptons of broadcasts and multicast..

                An intelligent man is sometimes forced to be drunk to spend time with his fools
                If you get confused: Listen to the Music Play
                Please don't Chat/PM me for help, unless mod related
                SG-4860 24.11 | Lab VMs 2.8, 24.11

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                  danldn31 @johnpoz
                  last edited by

                  @johnpoz I understand.
                  By network I meant two different subnets

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                  • johnpozJ
                    johnpoz LAYER 8 Global Moderator
                    last edited by johnpoz

                    That is implied its 2 different L2 networks.. You do not run multiple L3 networks on the same L2 - its BORKED!! especially with 2 different dhcp servers..

                    Do what I suggested and move the IP range to something new so you can use a /22 or /23 network if you need more IPs on the same network.

                    edit: Don't tell me the other networks you mention are all on the same L2??? That is why your not running dhcp on them???

                    An intelligent man is sometimes forced to be drunk to spend time with his fools
                    If you get confused: Listen to the Music Play
                    Please don't Chat/PM me for help, unless mod related
                    SG-4860 24.11 | Lab VMs 2.8, 24.11

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                    • D
                      danldn31 @johnpoz
                      last edited by danldn31

                      @johnpoz Yes, I think that's the right approach. Thank you.
                      Like I said, we have an unused interface OPT1, so I can just disable DHCP on LAN and enable DHCP on OPT1. We do have around 10-15 static mappings which then need to add it to the new DHCP interface.
                      After that, we will work on organizing our entire networks in a more proper way as @JeGr suggested.
                      Thank you

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                      • johnpozJ
                        johnpoz LAYER 8 Global Moderator
                        last edited by johnpoz

                        So this is just one big flat network with multiple layer 3 networks on it.. OMG.. what a cluster..

                        Do you have switches that support vlans? Do you have multiple switches?

                        If all you want is 1 big network, then do that - there is no reason to run multiple layer 3 networks if all you have is one L2.. You are not actually isolating anything from talking to each other if al your doing is using different IP schemes for different clients. So you might as well just put them on 1 network.

                        To properly segment clients, you need to do it at layer 2 first..

                        An intelligent man is sometimes forced to be drunk to spend time with his fools
                        If you get confused: Listen to the Music Play
                        Please don't Chat/PM me for help, unless mod related
                        SG-4860 24.11 | Lab VMs 2.8, 24.11

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