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

    Strange address Shown in the dhcp leases

    Scheduled Pinned Locked Moved General pfSense Questions
    57 Posts 12 Posters 14.1k 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.
    • H Offline
      hda
      last edited by

      @firefox:

      Could it be that someone is trying to get in to the network. Wirelessly ??

      If you are suspicious about (wireless) connections, then do ACL, explicitly allow MAC addresses (therefore deny the undefined) in your AP.

      1 Reply Last reply Reply Quote 0
      • F Offline
        firefox
        last edited by

        what is ACL ?

        1 Reply Last reply Reply Quote 0
        • H Offline
          hda
          last edited by

          Access Control List(s)

          In pfSense have look at Services: DHCP server [MAC Address Control]

          1 Reply Last reply Reply Quote 0
          • F Offline
            firefox
            last edited by

            @johnpoz:

            Why don't you look in the actual file for what it shows for the end date, and see what we have..

            example
            [2.2.2-RELEASE][root@pfSense.local.lan]/var/dhcpd/var/db: cat dhcpd.leases

            lease 192.168.2.216 {
              starts 6 2015/06/13 12:04:00;
              ends 3 2015/06/17 12:04:00;
              cltt 6 2015/06/13 12:04:00;
              binding state active;
              next binding state free;
              rewind binding state free;
              hardware ethernet ac:fd:ec:62:34:97;
              uid "\001\254\375\354b4\227";
              client-hostname "Johns-Phone";

            cltt stands for Client Last Transaction Time, not sure why its showing that vs the end date?  I would also track down what device it is, that is clearly an ODD mac..

            Where the last line ```
            client-hostname "Johns-Phone";

            
            It is not registered anything in the output of the command (in my computer)
            
            and now it is cltt 6
            
            

            lease 192.168.0.43 {
              starts 6 2015/06/13 21:31:09;
              ends never;
              cltt 6 2015/06/13 21:31:09;
              binding state active;
              next binding state free;
              rewind binding state free;
              hardware ethernet 00🆎00:00:00:00;

            
            How exactly do I use with this ACL option
            
            I have to enroll all Mac addresses of all computers on the network
            One by one comma separated
            
            it says partial MAC addresses
            Which part ?
            1 Reply Last reply Reply Quote 0
            • M Offline
              motionthings
              last edited by

              edit3
              My post was about wireless security, and did not belong here.
              I'll not be offended if it gets deleted. http://pastebin.com/QaGHXbU4
              /edit 3

              edit2
              Looks like @cmb has a really good answer. Thanks :-)
              /edit2

              Intel Core i3, 8GB RAM, 2x Intel Gigabit NIC's.
              CURRENT network: https://cacoo.com/diagrams/1Fh6EcMdZLjGq3zj
              Planned network: https://cacoo.com/diagrams/y2rMw37kzlzcHzZy
              Read BOFH (Bastard Operator From Hell): http://bofh.ntk.net/BOFH/index.php

              1 Reply Last reply Reply Quote 0
              • H Offline
                hda
                last edited by

                @firefox:

                …
                it says partial MAC addresses
                Which part ?

                http://www.gcstech.net/macvendor/index.php?node=macsea

                1 Reply Last reply Reply Quote 0
                • C Offline
                  cmb
                  last edited by

                  That's a BOOTP lease, which is why it looks weird.

                  Hostnames are only there where the client sends one. It not having one isn't unusual, especially for the types of devices that do BOOTP.

                  There are very limited devices that use BOOTP. Generally they're very old (1990s era printers for instance), or atypical embedded devices. It could be some broken device as well.

                  It seems to be a semi-active device, or at least your time of last contact (cltt) seems to update. If you have a managed switch, try tracking down that MAC address' port and see what's plugged into it. If you don't have a managed switch it'll be harder to track down, though not too difficult if you have a small network. Unplug most things, see if it's still updating. Add things back one by one. See when that comes back. Or just try reaching the device to see what it's running. A nmap scan with OS identification enabled might be telling.

                  1 Reply Last reply Reply Quote 0
                  • C Offline
                    cmb
                    last edited by

                    @Jailer:

                    checking now but even if it is why would it be set to never expire?

                    BOOTP leases never expire.

                    1 Reply Last reply Reply Quote 0
                    • C Offline
                      cmb
                      last edited by

                      That MAC seems to be something a number of other people have seen pulling BOOTP leases, though at a glance through Google results I don't see anyone who found the source of it. Might be worthwhile to dig through those results more closely.
                      https://www.google.com/webhp?q=%2200🆎00:00:00:00%22

                      1 Reply Last reply Reply Quote 0
                      • F Offline
                        firefox
                        last edited by

                        I know
                        Already encountered this once
                        Last time i  simply blocked the address

                        This time I wanted to know where it came from

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

                          well track it down – its clearly on your network..

                          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 25.07 | Lab VMs 2.8, 25.07

                          1 Reply Last reply Reply Quote 0
                          • F Offline
                            firefox
                            last edited by

                            I've checked
                            No device in my network
                            Have such address

                            That's why I ask

                            I blocked it again
                            As before

                            1 Reply Last reply Reply Quote 0
                            • JailerJ Offline
                              Jailer
                              last edited by

                              Yeah it's definitely not a device on my network, this is my home network and every device is accounted for.

                              Could it possibly be my Dlink router that I'm using as an AP? DHCP is turned off on the router but the wireless does occasionally quit working, especially when it gets warmer out, requiring a power cycle to restore it.

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

                                Sorry but its has to be something on your network..

                                Could be something like a media player, dvr, doubt its your dlink.. But sure..  When you delete the lease how long until it comes back?  Is it every 24 hours, every 1 hour, every 10 minutes?  Does it ping to that IP you gave it?

                                What interface are you seeing it on?  Lan, Wan, Wireless?  You don't have a smart switch that shows you mac address table?

                                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 25.07 | Lab VMs 2.8, 25.07

                                1 Reply Last reply Reply Quote 0
                                • JailerJ Offline
                                  Jailer
                                  last edited by

                                  Shows up on LAN, no smart switch. I'll have to check when I get home to see if it's back again. Had a power outage yesterday and as of last night it wasn't there.

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

                                    Is your lan bridged to your wireless?  If showing up on your lan - clearly its on your network ;)

                                    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 25.07 | Lab VMs 2.8, 25.07

                                    1 Reply Last reply Reply Quote 0
                                    • JailerJ Offline
                                      Jailer
                                      last edited by

                                      No bridge, just DHCP disabled and static IP so it's working as an AP. pfsense is handling all the routing.

                                      Checked my leases and it's not there any more. I dunno, maybe something left over from one of the many VM's I've had running? I'm out of ideas.

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

                                        So your wireless is on the same network as your lan - ie bridged..

                                        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 25.07 | Lab VMs 2.8, 25.07

                                        1 Reply Last reply Reply Quote 0
                                        • JailerJ Offline
                                          Jailer
                                          last edited by

                                          If that's what "bridged" means then yes. It is on the same subnet as LAN.

                                          1 Reply Last reply Reply Quote 0
                                          • F Offline
                                            firefox
                                            last edited by

                                            @johnpoz:

                                            Sorry but its has to be something on your network..

                                            Could be something like a media player, dvr, doubt its your dlink.. But sure..  When you delete the lease how long until it comes back?  Is it every 24 hours, every 1 hour, every 10 minutes?  Does it ping to that IP you gave it?

                                            What interface are you seeing it on?  Lan, Wan, Wireless?  You don't have a smart switch that shows you mac address table?

                                            Here is a list of all the addresses on my network
                                            1-27 are static addresses

                                            and 43 is Dynamic address

                                            If I shut down the DHCP
                                            I assume he could not get access to the network
                                            but Guests also can not

                                            If I delete this address
                                            After a while, it comes back
                                            Can be after 10 minutes
                                            Can be after two hours
                                            Can be after 16 hours
                                            No fixed time

                                            You can not ping to it

                                            PING 192.168.0.43 (192.168.0.43) 56(84) bytes of data.
                                            From 192.168.0.2 icmp_seq=1 Destination Host Unreachable
                                            From 192.168.0.2 icmp_seq=2 Destination Host Unreachable
                                            From 192.168.0.2 icmp_seq=3 Destination Host Unreachable
                                            From 192.168.0.2 icmp_seq=4 Destination Host Unreachable
                                            From 192.168.0.2 icmp_seq=5 Destination Host Unreachable
                                            From 192.168.0.2 icmp_seq=6 Destination Host Unreachable
                                            From 192.168.0.2 icmp_seq=7 Destination Host Unreachable
                                            From 192.168.0.2 icmp_seq=8 Destination Host Unreachable
                                            From 192.168.0.2 icmp_seq=9 Destination Host Unreachable
                                            
                                            

                                            I do not have a smart switch
                                            i see this address on my LAN
                                            i have WAN ,LAN, WIFI, and BRIDGE (lan and wifi)

                                            I have 2 routers that serve as an access point
                                            edimax 192.168.0.104
                                            dlink 192.168.0.101
                                            a network card on the pfsense also as AP (the wifi)
                                            and one cisco access point (192.168.0.25)
                                            all have fixed (static) IP
                                            DHCP shut down in the routers

                                            I went physically at home  to each device that connects to the network
                                            And checked Mack addresses the same as in the DHCP leases

                                            ![mac address.png](/public/imported_attachments/1/mac address.png)
                                            ![mac address.png_thumb](/public/imported_attachments/1/mac address.png_thumb)

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