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    DHCP no free leases

    Scheduled Pinned Locked Moved DHCP and DNS
    26 Posts 3 Posters 8.2k Views
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    • R Offline
      rovshango
      last edited by

      We just provide free Wi-Fi in random places.
      Mostly people connect with their hand devices and can login by generated password (SMS sending).

      Before me other person cleared dhcp leases file and problem solved.

      We had /24 at the beginning, but now we need more. So I changed network range.

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      • DerelictD Offline
        Derelict LAYER 8 Netgate
        last edited by

        And it sounds like you need more yet again.

        You need to balance the need to keep the lease history so people get the same IP versus the network size.

        Is there captive portal involved?

        If you don't really need those reserved 100 addresses I'd add those to the pool like now - or at least as many as you can.

        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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        • R Offline
          rovshango
          last edited by

          Yes CP is main part :)

          10.64.160.0/22 (255.255.252.0) means there 1022 available address (10.64.160.0 - 10.64.163.255)
          I can see in daily report that there are maximum 200 users.
          And this error I got week ago and today.

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          • DerelictD Offline
            Derelict LAYER 8 Netgate
            last edited by

            You have a max DHCP lease timeout of 3660 seconds (61 minutes).

            Regardless of the maximum on the CP at one time, how many devices are connecting to your Wi-Fi and getting an address in your busiest hour?  Note that they don't have to punch through the portal to chew up a DHCP lease.

            How do you want your CP to behave?

            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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            • R Offline
              rovshango
              last edited by

              I can say busies hour there will be 100-200 user same time.
              Also in attachment you can find settings of CP.

              As there 1022 (-100) available address, I want users to get IP addresses.

              cp_rovshan.JPG
              cp_rovshan.JPG_thumb

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              • DerelictD Offline
                Derelict LAYER 8 Netgate
                last edited by

                You are running out of leases, friend.  Something is chewing them up.

                I say again, a user doesn't have to log in to the CP to consume a DHCP lease for an hour.  All they have to do is connect to the BSSID and get a lease.  Unfortunately, ISC dhcpd absolutely SUCKS when it comes to summarizing exactly what is going on with your lease pool.

                Something like this: http://dhcpstatus.sourceforge.net/

                might give you some additional insight as to exactly what is happening to your lease pool.

                If you're not syslogging to a syslog server you probably want to do that too.  My dhcp log on pfSense rolls over about every 5 minutes.

                900 leases with an hour expire seems like it ought to be enough.

                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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                • R Offline
                  rovshango
                  last edited by

                  Yeah, that part I understand, that user gets IP address first then CP starts to working,
                  I just want each IP address after 60 minutes to be freed :(

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                  • DerelictD Offline
                    Derelict LAYER 8 Netgate
                    last edited by

                    That's how you have it set.  That's how it should be working.

                    Note that those settings take effect when the lease is obtained so if you just changed it it will take some time to take effect.

                    Status > DHCP Leases shows you the current leases.  Do they not look right?

                    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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                    • R Offline
                      rovshango
                      last edited by

                      It shows 423 online&active and same time I am getting same alarm :(.

                      Well when before this topic I cleaned dhcpd.leases file but it got filled with old data again.

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                      • DerelictD Offline
                        Derelict LAYER 8 Netgate
                        last edited by

                        What shows 423 online and active?  The DHCP leases?

                        You have to account for the offline leases that haven't expired yet.  As far as I know, Status > DHCP Leases shows a lease as offline if there is no corresponding ARP entry, meaning the IP has dropped off the network.

                        Obviously you need a bigger lease pool.

                        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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                        • R Offline
                          rovshango
                          last edited by

                          Thanks for info.
                          So I will change network range then.
                          Let's see what will happen.

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                          • R Offline
                            rovshango
                            last edited by

                            Hi all,

                            Very strange - CP shows me only 40 active users.
                            But I am getting same syslog again.

                            Despite there are almost 1000 free IP addresses.

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                            • DerelictD Offline
                              Derelict LAYER 8 Netgate
                              last edited by

                              How do you know what addresses are free?

                              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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                              • R Offline
                                rovshango
                                last edited by

                                You mean, even though if CP will disconnect them, they will use IP address till lease time?

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                                • DerelictD Offline
                                  Derelict LAYER 8 Netgate
                                  last edited by

                                  Of course.  CP has nothing to do with DHCP.  They have to play together nicely and be set up in a complementary fashion but one doesn't influence the other.  Look into those dhcp status scripts I posted earlier.

                                  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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                                  • R Offline
                                    rovshango
                                    last edited by

                                    Well my CP set for 59 minutes, so I should set DHCP lease time also 59 minutes.
                                    Then I think lease/pool will be freed correctly.

                                    Yes I saw your post, I had difficulties installed in into pfSense, as there some library dependencies. I will try again :)

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                                    • DerelictD Offline
                                      Derelict LAYER 8 Netgate
                                      last edited by

                                      What CP is set for 59 minutes?  In these matters specifics count.

                                      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)

                                      1 Reply Last reply Reply Quote 0
                                      • DerelictD Offline
                                        Derelict LAYER 8 Netgate
                                        last edited by

                                        And FWIW I didn't hassle trying to get the DHCP status running on pfSense - screw with your router as little as possible.  I got it running on my Mac and scp'd the leases file over and ran it there occasionally until I was confident I had things right.  If you don't have a Unix host to run things like this, install Linux, FreeBSD, or even pfSense on something else and install stuff on that.

                                        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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                                        • R Offline
                                          rovshango
                                          last edited by

                                          Hi,

                                          I changed DHCP lease time, you can see CP and DHCP configurations.
                                          Seem I do not get same log, but I am getting another one now :)
                                          See attachment syslog.jpg

                                          CP.JPG
                                          dhcp.JPG
                                          syslog.JPG
                                          CP.JPG_thumb
                                          dhcp.JPG_thumb
                                          syslog.JPG_thumb

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                                          • DerelictD Offline
                                            Derelict LAYER 8 Netgate
                                            last edited by

                                            Those happen.  They appear harmless.

                                            There is no use having an idle timeout of 59 with a hard timeout of 59.  Are you sure your idle timeout of 59 isn't good enough?  That means a user who is gone from your network for 59 minutes is logged out.

                                            What are your goals for your captive portal?

                                            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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