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    DHCP failing when moving between AP's

    Scheduled Pinned Locked Moved DHCP and DNS
    dhcpunifiaccess point
    13 Posts 4 Posters 2.4k Views
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    • DerelictD
      Derelict LAYER 8 Netgate
      last edited by Derelict

      "Roaming" between APs does not require a new DHCP lease. The client just continues to use the same lease.

      If pfSense is not even seeing a DISCOVER/REQUEST when one is necessary you need to look at the layer 2 - the controller, switches, and APs to see what's going on there.

      dhcpd cannot answer a request it never receives.

      I would capture on a SPAN/Mirror port on the switch to see if the AP is sending the DHCP DISCOVER/REQUEST from the client.

      10 minutes is really short. If you don't have a lot of client churn I'd increase that to at least 3600 seconds (1 hour). At 10 minutes you could possibly be confusing some DHCP clients but that's pretty much a guess.

      The WPA2 Enterprise RADIUS authentication would have to succeed before a lease request would be put on the network. But it sounds like this is happening on both SSIDs.

      Chattanooga, Tennessee, USA
      A comprehensive network diagram is worth 10,000 words and 15 conference calls.
      DO NOT set a source address/port in a port forward or firewall rule unless you KNOW you need it!
      Do Not Chat For Help! NO_WAN_EGRESS(TM)

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      • J
        jafr @Derelict
        last edited by

        @derelict
        Regarding the REQUEST that's exactly what I'm thinking. It makes complete sense that it doesn't receive an IP when there's no REQUEST for it.
        I just don't understand why the REQUEST comes in when I set an IP on my device, but not if I set my device to receive the IP from the DHCP.

        The problem is happening on both SSID's yes, so I don't think the FreeRADIUS is the problem.

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        • DerelictD
          Derelict LAYER 8 Netgate
          last edited by Derelict

          If you set a static IP address there is no REQUEST because there is no DHCP.

          https://en.wikipedia.org/wiki/Dynamic_Host_Configuration_Protocol

          Chattanooga, Tennessee, USA
          A comprehensive network diagram is worth 10,000 words and 15 conference calls.
          DO NOT set a source address/port in a port forward or firewall rule unless you KNOW you need it!
          Do Not Chat For Help! NO_WAN_EGRESS(TM)

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          • J
            jafr @Derelict
            last edited by jafr

            @derelict
            That makes a lot more sense then.
            I'm thinking the problem is occuring with the switch it is connected to, given that the same AP works without issues when set up on another port of the switch, and other APs are failing on the same port as well.

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            • DerelictD
              Derelict LAYER 8 Netgate
              last edited by Derelict

              Some managed switches have higher-layer code for things like DHCP snooping and abuse prevention. I'd look there.

              The fact that setting a static IP address always works leads me to believe that you have good layer 2 between the APs (and the clients) and the firewall port. So it must be something at a higher layer.

              Chattanooga, Tennessee, USA
              A comprehensive network diagram is worth 10,000 words and 15 conference calls.
              DO NOT set a source address/port in a port forward or firewall rule unless you KNOW you need it!
              Do Not Chat For Help! NO_WAN_EGRESS(TM)

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              • GertjanG
                Gertjan
                last edited by Gertjan

                Hi,

                What exactly is the problem ?

                Client did ask for an IP, and didn't get one ?

                Oops - didn't saw the 3 replies ...

                No "help me" PM's please. Use the forum, the community will thank you.
                Edit : and where are the logs ??

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                • J
                  jafr @Gertjan
                  last edited by

                  @gertjan
                  Hi,

                  Well, the problem is that a REQUEST isn't sent to the DHCP server from one (mainly) AP, when clients are connecting to it, even though it's working like a charm on the other APs in the building that are connecting to the same DHCP server.

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                  • GertjanG
                    Gertjan
                    last edited by

                    Between this "AP" and pfSense "smart" switch ?
                    What happens when you change it for a less-smarter switch ? ;)

                    No "help me" PM's please. Use the forum, the community will thank you.
                    Edit : and where are the logs ??

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                    • J
                      jafr @Gertjan
                      last edited by

                      @gertjan
                      The Switch is an HP 2530 PoE switch, and it is the only PoE device I have available at the moment, so I can't test with a "dumb" switch unfortunately.

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                      • johnpozJ
                        johnpoz LAYER 8 Global Moderator
                        last edited by

                        @jafr said in DHCP failing when moving between AP's:

                        HP 2530

                        Quick look shows that that switch can do dhcp snooping since I see in the manual dhcp snooping events for snmp.. So you need to look at the configuration of that switch or the port your AP is connected to.

                        If pfsense does not see the discover for dhcp then no it would never offer an IP..

                        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
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