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    Not getting DHCP lease from Netgear LB1120 LTE Modem Bridged

    Scheduled Pinned Locked Moved Routing and Multi WAN
    28 Posts 3 Posters 1.9k Views
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    • chpalmerC
      chpalmer @mrn
      last edited by

      @mrn can you show a screenshot of your modem interface WAN page?

      Assuming you are absolutely not getting an IP? Not just a connectivity problem?

      Triggering snowflakes one by one..
      Intel(R) Core(TM) i5-4590T CPU @ 2.00GHz on an M400 WG box.

      chpalmerC 1 Reply Last reply Reply Quote 0
      • chpalmerC
        chpalmer @chpalmer
        last edited by

        Also.. look up the MTU for the carrier you are using.. Verizon is 1400. Wont affect the DHCP but will affect traffic.

        Triggering snowflakes one by one..
        Intel(R) Core(TM) i5-4590T CPU @ 2.00GHz on an M400 WG box.

        M 1 Reply Last reply Reply Quote 0
        • M
          mrn @chpalmer
          last edited by

          @chpalmer

          Here's my pfsense interface:

          interface.png

          Here's my LTE modem configuration (I didn't see any other sections of importance):

          Screenshot from 2025-03-24 23-27-49.png
          Screenshot from 2025-03-24 23-28-09.png

          As you can see from the following image, my laptop got the bridged IP address correctly. Oddly enough, I didn't have to reboot the LTE modem to get this IP.... I wonder if it's permanently tied to my laptop MAC address even through reboots? That doesn't seem right.

          Screenshot from 2025-03-24 23-40-38.png

          M 1 Reply Last reply Reply Quote 0
          • M
            mrn @mrn
            last edited by

            It's not the cable either. I just used the same cable for the router and laptop.

            M 1 Reply Last reply Reply Quote 0
            • M
              michmoor LAYER 8 Rebel Alliance @mrn
              last edited by

              @mrn that’s a weird one. I would look into that system logs to see what’s going on (dhclient) with DHCP.

              Firewall: NetGate,Palo Alto-VM,Juniper SRX
              Routing: Juniper, Arista, Cisco
              Switching: Juniper, Arista, Cisco
              Wireless: Unifi, Aruba IAP
              JNCIP,CCNP Enterprise

              M 1 Reply Last reply Reply Quote 0
              • M
                mrn @michmoor
                last edited by

                @michmoor I already did that in my first post, unless you mean some other place.

                M 1 Reply Last reply Reply Quote 0
                • M
                  michmoor LAYER 8 Rebel Alliance @mrn
                  last edited by michmoor

                  @mrn yes i see that i apologize.
                  This doesnt seem like a pfsense related issue.
                  DHCP is 4 message types
                  Discover
                  Offer
                  Request
                  Acknowledgement

                  pfSense is sending out a broadcast looking for a dhcp server. The dhcp server (cable modem) will hear that broadcast and respond with an offer (public IP from the pool).
                  From your system log messages (assuming no filtering of the log messages), pfsense is looking for the dhcp server and its not responding.
                  As mentioned it could be a sticky mac address issue where the first record mac learned on the cable modem port is what will get the IP address and subsequent macs get nothing. If so and if rebooting the modem doesnt clear the mac then i would contact the service provider.

                  edit: Why are you hard coding a mac address in the pfsense WAN DHCP settings?

                  Firewall: NetGate,Palo Alto-VM,Juniper SRX
                  Routing: Juniper, Arista, Cisco
                  Switching: Juniper, Arista, Cisco
                  Wireless: Unifi, Aruba IAP
                  JNCIP,CCNP Enterprise

                  M 1 Reply Last reply Reply Quote 0
                  • M
                    mrn @michmoor
                    last edited by

                    @michmoor

                    The reason I hardcoded it is that I have an high availability setup. Right now the LTE modem is connected to my secondary pfsense, but I want to me able to move the connection to the primary if necessary. I know that having the same MAC address can make it a seamless transition.

                    M 1 Reply Last reply Reply Quote 0
                    • M
                      mrn @mrn
                      last edited by

                      It won't pull an neither on bridged NOR on router mode.

                      M 1 Reply Last reply Reply Quote 0
                      • M
                        mrn @mrn
                        last edited by

                        @mrn And yes, I have updated it to the latest firmware version.

                        M 1 Reply Last reply Reply Quote 0
                        • M
                          michmoor LAYER 8 Rebel Alliance @mrn
                          last edited by

                          @mrn in Router mode i suspect the cable modem is giving out a DHCP address in the RFC1918 space which based on your screenshot, pfsense will ignore. Uncheck that option and test again.

                          Firewall: NetGate,Palo Alto-VM,Juniper SRX
                          Routing: Juniper, Arista, Cisco
                          Switching: Juniper, Arista, Cisco
                          Wireless: Unifi, Aruba IAP
                          JNCIP,CCNP Enterprise

                          M 1 Reply Last reply Reply Quote 0
                          • M
                            mrn @michmoor
                            last edited by

                            @michmoor Believe it or not, it STILL doesn't pull a DHCP lease.

                            I'm about to return this thing and try something else.

                            chpalmerC 2 Replies Last reply Reply Quote 0
                            • chpalmerC
                              chpalmer @mrn
                              last edited by

                              @mrn uncheck the two boxes for the reserved addresses on your WAN page.

                              Triggering snowflakes one by one..
                              Intel(R) Core(TM) i5-4590T CPU @ 2.00GHz on an M400 WG box.

                              1 Reply Last reply Reply Quote 0
                              • chpalmerC
                                chpalmer @mrn
                                last edited by

                                @mrn
                                This is how mine is set up.

                                WAN2.png

                                Triggering snowflakes one by one..
                                Intel(R) Core(TM) i5-4590T CPU @ 2.00GHz on an M400 WG box.

                                M 1 Reply Last reply Reply Quote 0
                                • M
                                  mrn @chpalmer
                                  last edited by mrn

                                  @chpalmer

                                  My modem is haunted. Which model do you use?

                                  Screenshot from 2025-03-25 18-49-14.png

                                  Screenshot from 2025-03-25 18-51-15.png

                                  I rebooted the modem, I rebooted pfsense. It just does not work!!

                                  M chpalmerC 3 Replies Last reply Reply Quote 0
                                  • M
                                    michmoor LAYER 8 Rebel Alliance @mrn
                                    last edited by

                                    @mrn
                                    Desperation.
                                    Try another port other than igb3

                                    Firewall: NetGate,Palo Alto-VM,Juniper SRX
                                    Routing: Juniper, Arista, Cisco
                                    Switching: Juniper, Arista, Cisco
                                    Wireless: Unifi, Aruba IAP
                                    JNCIP,CCNP Enterprise

                                    M 1 Reply Last reply Reply Quote 0
                                    • chpalmerC
                                      chpalmer @mrn
                                      last edited by

                                      @mrn said in Not getting DHCP lease from Netgear LB1120 LTE Modem Bridged:

                                      @chpalmer

                                      My modem is haunted. Which model do you use?

                                      I also use the Netgear LB1120

                                      Triggering snowflakes one by one..
                                      Intel(R) Core(TM) i5-4590T CPU @ 2.00GHz on an M400 WG box.

                                      1 Reply Last reply Reply Quote 0
                                      • chpalmerC
                                        chpalmer @mrn
                                        last edited by

                                        @mrn Quit trying to spoof the MAC address.. Not sure why you would need it.

                                        Triggering snowflakes one by one..
                                        Intel(R) Core(TM) i5-4590T CPU @ 2.00GHz on an M400 WG box.

                                        1 Reply Last reply Reply Quote 0
                                        • M
                                          mrn @michmoor
                                          last edited by

                                          @michmoor

                                          A different port works!!!

                                          Thank you all!

                                          M 1 Reply Last reply Reply Quote 0
                                          • M
                                            michmoor LAYER 8 Rebel Alliance @mrn
                                            last edited by

                                            @mrn
                                            nice..
                                            dont know whats going on with igb3 in that case but glad its all sorted.

                                            Firewall: NetGate,Palo Alto-VM,Juniper SRX
                                            Routing: Juniper, Arista, Cisco
                                            Switching: Juniper, Arista, Cisco
                                            Wireless: Unifi, Aruba IAP
                                            JNCIP,CCNP Enterprise

                                            M 1 Reply Last reply Reply Quote 0
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