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

    [SOLVED] 2 SSID with different subnets - DHCP NAK

    Scheduled Pinned Locked Moved DHCP and DNS
    18 Posts 3 Posters 788 Views
    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.
    • johnpozJ
      johnpoz LAYER 8 Global Moderator
      last edited by johnpoz

      You validated that client is getting the NAK? Seeing that the dhcpd sent it is only half the battle.. When a client doesn't get a nak.. It could assume that the IP is still good and will continue to try and use it.

      but Unifi controller confirms in webui that client got DHCP NAK

      How is that?? I have unifi controller - and have never seen any info it at all about dhcp anywhere

      So that link looks like there is a bug on your linux networkmanager - looks like it is fixed from post a day ago with specific commit.
      "This should be fixed by !387."

      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 2.7.2, 24.11

      1 Reply Last reply Reply Quote 0
      • P
        pszafer
        last edited by pszafer

        I see it. It will be available any minute now. It is already in main repo https://www.archlinux.org/packages/extra/x86_64/networkmanager/ and I'm waiting when it will be available on all mirrors.

        @johnpoz about Unifi
        I have DHCP Snooping enabled and if you get DHCP NAK, then it shows up in Topology map.Instead of green line it is red, with info about DHCP NAK.

        Thank you again for your help!

        1 Reply Last reply Reply Quote 0
        • johnpozJ
          johnpoz LAYER 8 Global Moderator
          last edited by johnpoz

          Ah - yeah I don't have that on... See no point to it in my setup. But will check it out thanks!

          You have unifi switches? I don't so that setting makes no sense in my setup.

          edit: But your saying these would show red?

          allgreen.jpg

          And if you highlight them or something shows that there was a nak.. From my quick look into dhcp snooping on unifi, other than lots of people complaining about bugs with it.. You need to have unifi switches it seems, nothing done on the AP.

          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 2.7.2, 24.11

          P 1 Reply Last reply Reply Quote 0
          • P
            pszafer @johnpoz
            last edited by

            @johnpoz I had to wait to see red line and get back to you.
            Anyway I see red line and info that there is DHCP Timeout. Check dhcp settings on your router. On pfsense I see DHCP NAK.
            I don't have Unifi switches.

            1 Reply Last reply Reply Quote 0
            • johnpozJ
              johnpoz LAYER 8 Global Moderator
              last edited by

              Where do you have this snooping enabled exactly? My understanding does nothing if you don't have their switches, same with the dhcp guarding.

              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 2.7.2, 24.11

              P 1 Reply Last reply Reply Quote 0
              • P
                pszafer @johnpoz
                last edited by

                @johnpoz

                Settings -> Site -> Services section -> DHCP Snooping
                

                ff574820-261b-41a7-967a-fac8a8f67f9b-image.png

                On option which requires Unifi Gateway there is info USG REQUIRED.

                1 Reply Last reply Reply Quote 0
                • johnpozJ
                  johnpoz LAYER 8 Global Moderator
                  last edited by

                  Ok no switches, but a USG is required - don't have that.. Do you, thought you were running pfsense?

                  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 2.7.2, 24.11

                  P 1 Reply Last reply Reply Quote 0
                  • P
                    pszafer @johnpoz
                    last edited by

                    @johnpoz this feature doesn't need USG. I have only 3 Unifi AP-AC-Pro, nothing else from Unifi.

                    1 Reply Last reply Reply Quote 0
                    • johnpozJ
                      johnpoz LAYER 8 Global Moderator
                      last edited by johnpoz

                      I don't see that anywhere in the new ui.. But I find it on the old ui..

                      It is enabled on mine, I think its default... But I find it unlikely the AP would do anything with that setting. I have never seen such an issue - All of my ssids are different IPs.. I have devices that move between these networks without issue, I have moved laptop from wired to wireless - again different vlans, never an issue..

                      So lets start again... On the client sniffing do you see the offer? Do you see the nak? Do you see it send a discover after nak?

                      On the wire before it goes to the AP do you see the nak, do you see an offer, etc..

                      What is your dhcp server? Pfsense, the controller? Something else?

                      If you think unifi is doing something with the dhcp traffic that you don't want it to - then you should get with them about the problem. If pfsense is your dhcpd, and you see it send the nak, there is nothing else pfsense could do if the client doesn't see that, or doesn't then do a discover, etc.

                      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 2.7.2, 24.11

                      1 Reply Last reply Reply Quote 0
                      • P
                        pszafer
                        last edited by

                        I think there is misunderstanding. I edited subject to SOLVED, but I've should post info, that fix included in NetworkManager 1.22.4 solves this problem, it doesn't exists anymore.

                        I just wanted to reply to you what I see in Unifi web ui.

                        1 Reply Last reply Reply Quote 0
                        • johnpozJ
                          johnpoz LAYER 8 Global Moderator
                          last edited by

                          Ok so was that client bug then.. Great..

                          Well like I said I can not find that on the "beta" ui, but I do see it on the classic view.. I do not recall ever enabling that, nor would I have reason to.. And some threads I found people complaining that it is on by default, etc..

                          Glad you got it sorted in the end..

                          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 2.7.2, 24.11

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