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    Request for dhcp from strange address?

    Scheduled Pinned Locked Moved DHCP and DNS
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    • johnpozJ Offline
      johnpoz LAYER 8 Global Moderator
      last edited by

      Here is the thing, just because IP range is owned by company xyz.. Doesn't mean its really them.. There are lots and lots of people that use IP address they pull out of thin are with no concern to actually owns it.

      If you have concerns contact your ISP..  But more than likely its some idiot..  Here is the the thing traffic from that box can not go anywhere other than the local layer 2 its on..

      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 25.07.1 | Lab VMs 2.8.1, 25.07.1

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      • JKnottJ Offline
        JKnott
        last edited by

        It only shows in the firewall log, not in the dhcp log.

        That only shows the firewall is doing it's job.  It shouldn't be allowing DHCP requests from the WAN.

        PfSense running on Qotom mini PC
        i5 CPU, 4 GB memory, 32 GB SSD & 4 Intel 1 Gb Ethernet ports.
        UniFi AC-Lite access point

        I haven't lost my mind. It's around here...somewhere...

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        • J Offline
          JonH
          last edited by

          I'd like to thank everyone for their responses here.  They were very helpful.

          Even tho I have maintained a connection on my WAN with the strange IP that I had blocked, once I unblocked it, pfSense immediately issued a DHCPREQUEST to a different Charter Communications server than it usually sends to (not the same subnet that was blocked).

          So I'll accept it as it is, I don't understand how it is all interconnected, the fact that that IP was owned by the DoD had me scratching my head.  It all seems to be working so I'll leave well enough alone.

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          • JKnottJ Offline
            JKnott
            last edited by

            Given that the Internet started as a Dept of Defense research project, a lot of addresses were "owned" by the DoD.  When it first started, the 'net was used only by military contractors and researchers, including some universities.

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

            PfSense running on Qotom mini PC
            i5 CPU, 4 GB memory, 32 GB SSD & 4 Intel 1 Gb Ethernet ports.
            UniFi AC-Lite access point

            I haven't lost my mind. It's around here...somewhere...

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            • J Offline
              JonH
              last edited by

              I would think that ARIN WHOIS data is relatively up to date.  Maybe I expect too much ::)

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              • JKnottJ Offline
                JKnott
                last edited by

                Hmmm…

                Whatismyipaddress.com shows it's DoD, located in Utah.  Maybe it has something to do with Area 51.  ;-)

                https://en.wikipedia.org/wiki/Dugway_Proving_Ground#UFO_speculation

                PfSense running on Qotom mini PC
                i5 CPU, 4 GB memory, 32 GB SSD & 4 Intel 1 Gb Ethernet ports.
                UniFi AC-Lite access point

                I haven't lost my mind. It's around here...somewhere...

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                • johnpozJ Offline
                  johnpoz LAYER 8 Global Moderator
                  last edited by

                  Area 51 is in Nevada ;)  Groom Lake!

                  Yeah ARIN is pretty up to date.. Not sure they would have a wrong listing for 30 address..  Are you saying you got your dhcp IP from this IP address??  I am confused on what this address has to do with anything to be honest?  Or what does it matter?  Maybe the dod uses your same ISP??  And they are running multiple layer 3 networks on the same layer 2 ;)

                  What that looks like is a dhcpack.. So your saying that is what is giving you your IP??  Then either your ISP is the DOD ;)  Or what is more likely is they are using IPs that are not theirs because they don't think anyone will be talking to those IPs..  While its BAD practice, it is common practice..  Again its BAD practice.. but happens more than you think.. Companies to lazy to do proper IPAM or subnetting or natting when required..  Hey lets grab these /8's that are owned by DOD - nobody is going to be going there ;)

                  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 25.07.1 | Lab VMs 2.8.1, 25.07.1

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                  • JKnottJ Offline
                    JKnott
                    last edited by

                    Area 51 is in Nevada ;)  Groom Lake!

                    From the article "[Dugway is] the new Area 51. And probably the new military spaceport.".  ;)

                    Or what is more likely is they are using IPs that are not theirs because they don't think anyone will be talking to those IPs..

                    My cell carrier did that prior to switching over to IPv6.  I'd get an address in the 25 block, IIRC, which NATed to the 24 block.  Now my phone is IPv6 only and uses 464XLAT to provide IPv4 access.

                    https://en.wikipedia.org/wiki/IPv6_transition_mechanism#464XLAT

                    PfSense running on Qotom mini PC
                    i5 CPU, 4 GB memory, 32 GB SSD & 4 Intel 1 Gb Ethernet ports.
                    UniFi AC-Lite access point

                    I haven't lost my mind. It's around here...somewhere...

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                    • johnpozJ Offline
                      johnpoz LAYER 8 Global Moderator
                      last edited by

                      Oh you meant R-6413 ;)  Yeah that is in Utah…

                      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 25.07.1 | Lab VMs 2.8.1, 25.07.1

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                      • J Offline
                        JonH
                        last edited by

                        @johnpoz:

                        Yeah ARIN is pretty up to date.. Not sure they would have a wrong listing for 30 address..  Are you saying you got your dhcp IP from this IP address??  I am confused on what this address has to do with anything to be honest?  Or what does it matter?  Maybe the dod uses your same ISP??  And they are running multiple layer 3 networks on the same layer 2 ;)

                        I'm confused too, that is why I posted here looking for suggestions.  My logs have wrapped around since I started this so I don't have documentation now.

                        This is a typical entry from dhcp log.  I do note the acknowledging server is from a different IP than yesterday but this IP is registered to my ISP, which is the cable company Charter Communications.  My connection is via cable modem.

                        Nov 21 04:07:42 	dhclient 	27954 	DHCPREQUEST on igb0 to 68.114.36.9 port 67
                        Nov 21 04:07:42 	dhclient 	27954 	DHCPACK from 68.114.36.9
                        Nov 21 04:07:42 	dhclient 		RENEW
                        Nov 21 04:07:42 	dhclient 		Creating resolv.conf
                        Nov 21 04:07:42 	dhclient 	27954 	bound to x.x.x.x -- renewal in 12752 seconds.
                        Nov 21 04:41:30 	dhcpd 		Wrote 0 deleted host decls to leases file.
                        Nov 21 04:41:30 	dhcpd 		Wrote 0 new dynamic host decls to leases file.
                        Nov 21 04:41:30 	dhcpd 		Wrote 16 leases to leases file. 
                        

                        What that looks like is a dhcpack.. So your saying that is what is giving you your IP??  Then either your ISP is the DOD ;)  Or what is more likely is they are using IPs that are not theirs because they don't think anyone will be talking to those IPs..  While its BAD practice, it is common practice..  Again its BAD practice.. but happens more than you think.. Companies to lazy to do proper IPAM or subnetting or natting when required..  Hey lets grab these /8's that are owned by DOD - nobody is going to be going there ;)

                        Or for the really paranoid, it's the NSC's backdoor into a large US customer base.

                        I cannot say that 30.85.128.1 is giving me my IP.  For the last month or so I've noticed everytime my lease was renewed there is a message in the log that there are 2 dhcp servers.  That is news to me.  But now that I have found this DoD server maybe that is the cause of that message.

                        I can only say that this IP is in my firewall log.  My dhcp log shows my request being ack by Charter's IP.  I first discovered this when I did a halt on pfSense so I could relocate the SG2440.  I then looked at the logs after restarting, I had never done a cold startup since putting it into service.  I found that odd IP in the firewall log about the same point in time that my DHCP request was being ACK.  I didn't recognize it and did a whois.  That started this thread.  I blocked that IP and it continued to hammer 2x every 10 minutes throughout the night.  I recently unblocked that rule.

                        Now that I've been through this discussion and looked at the logs for awhile, I'd have to repeat that cold startup and capture the logs to review.  I think it's pretty crazy.

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                        • JKnottJ Offline
                          JKnott
                          last edited by

                          Hey lets grab these /8's that are owned by DOD - nobody is going to be going there

                          Except aliens.  ;)

                          PfSense running on Qotom mini PC
                          i5 CPU, 4 GB memory, 32 GB SSD & 4 Intel 1 Gb Ethernet ports.
                          UniFi AC-Lite access point

                          I haven't lost my mind. It's around here...somewhere...

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                          • johnpozJ Offline
                            johnpoz LAYER 8 Global Moderator
                            last edited by

                            I don't see how its crazy.. Since this is broadcast traffic and can only be on layer 2, which is your ISP.. Contact your ISP if your curious/concerned.  But going to say this yet again.  Just because the IP is registered to the DOD doesn't mean its not your ISP using it, or could just be some idiot down the street running a dhcp server on his wan and he is using dod address space..

                            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 25.07.1 | Lab VMs 2.8.1, 25.07.1

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                            • D Offline
                              doktornotor Banned
                              last edited by

                              @johnpoz:

                              could just be some idiot down the street running a dhcp server on his wan and he is using dod address space..

                              One, two, three of them just here on the forum…

                              ;D ;D ;D

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                              • johnpozJ Offline
                                johnpoz LAYER 8 Global Moderator
                                last edited by

                                ^ heheh exactly!!!  So see if they plugged that interface into their isp device the wrong way.. Big Bang Zoom there you go a dod address space dhcp server on some ISP layer 2 network.  Where all the users on that network could see the traffic..  Hopefully they don't get an IP from it ;)  You would HOPE!!!! That the isp is running stuff to prevent unauthorized dhcp servers on the layer 2 between them and their customers.  But you never know….

                                So what I would do is email your isp support, showing them dhcp traffic and the IP and asking if that is them...  Or one of their other idiot users..

                                Whats the mac address coming from that 30 address?  We can look it up and see what kind of hardware it is, or the maker of it..

                                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 25.07.1 | Lab VMs 2.8.1, 25.07.1

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                                • J Offline
                                  JonH
                                  last edited by

                                  @johnpoz:

                                  Whats the mac address coming from that 30 address?  We can look it up and see what kind of hardware it is, or the maker of it..

                                  So I would need to have a packet trace running at the moment in time that the misconfigured device makes a request?  Or is there another way that I am not thinking about?

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                                  • K Offline
                                    kpa
                                    last edited by

                                    ARP table, it's there exactly for the purpose of seeing the MAC addresses of network peers on the same network segment.

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                                    • JKnottJ Offline
                                      JKnott
                                      last edited by

                                      ^^^^
                                      An arp cache has a limited lifetime, so he'd have to check it within a short period of time.  However, if he can ping that address and get a response, the arp cache would have the MAC.  Failing that, just let the packet capture run, filtering on that IP address.

                                      PfSense running on Qotom mini PC
                                      i5 CPU, 4 GB memory, 32 GB SSD & 4 Intel 1 Gb Ethernet ports.
                                      UniFi AC-Lite access point

                                      I haven't lost my mind. It's around here...somewhere...

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                                      • J Offline
                                        JonH
                                        last edited by

                                        The IP does not respond to a ping.  But my ISP's dhcp does respond to a ping.

                                        I think the only option is a packet capture.  Not sure I want to leave it running for an extended period of time.

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                                        • chpalmerC Offline
                                          chpalmer
                                          last edited by

                                          @johnpoz:

                                          ^ heheh exactly!!!

                                          +1

                                          Had a large fire agency in my county trying to hand out DHCP to cable system customers for almost two weeks till the techs paid them a visit.  ;D ::)

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

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                                          • K Offline
                                            kpa
                                            last edited by

                                            At least my ISP is sneaky enough to isolate its clients from each other:

                                            
                                            $ ifconfig em1
                                            em1: flags=8843 <up,broadcast,running,simplex,multicast>metric 0 mtu 1500
                                                    options=209b <rxcsum,txcsum,vlan_mtu,vlan_hwtagging,vlan_hwcsum,wol_magic>ether 00:1b:21:14:ca:5e
                                                    inet6 fe80::21b:21ff:fe14:ca5e%em1 prefixlen 64 scopeid 0x3
                                                    inet 88.xxx.yyy.181 netmask 0xffffe000 broadcast 88.xxx.zzz.255
                                                    inet 192.168.1.200 netmask 0xffffff00 broadcast 192.168.1.255
                                                    nd6 options=21 <performnud,auto_linklocal>media: Ethernet autoselect (100baseTX <full-duplex>)
                                                    status: active
                                            
                                            $ ping 88.xxx.yyy.182
                                            PING 88.xxx.yyy.182 (88.xxx.yyy.182): 56 data bytes
                                            ^C
                                            --- 88.xxx.yyy.182 ping statistics ---
                                            1 packets transmitted, 0 packets received, 100.0% packet loss
                                            
                                            $ arp -an
                                            ...
                                            ? (88.xxx.yyy.182) at 00:0b:45:b6:ef:c0 on em1 expires in 1058 seconds [ethernet]
                                            ? (88.xxx.yyy.181) at 00:1b:21:14:ca:5e on em1 permanent [ethernet]
                                            ? (88.xxx.yyy.1) at 00:0b:45:b6:ef:c0 on em1 expires in 90 seconds [ethernet]
                                            ...</full-duplex></performnud,auto_linklocal></rxcsum,txcsum,vlan_mtu,vlan_hwtagging,vlan_hwcsum,wol_magic></up,broadcast,running,simplex,multicast> 
                                            

                                            The .181 is my current IP address and the .1 address is the gateway on the WAN network and it (or more likely some equipment between me and the gateway device) seems to just proxy ARP every single IP address of the WAN network that is not assigned to you.

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