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

    SG-1100 - Ntopng Network Discovery finds strange 15.xxx addresses on disconnected OPT port

    Scheduled Pinned Locked Moved General pfSense Questions
    28 Posts 7 Posters 2.3k Views 8 Watching
    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.
    • ? Offline
      A Former User @johnpoz
      last edited by

      This post is deleted!
      1 Reply Last reply Reply Quote 0
      • dennypageD Offline
        dennypage
        last edited by

        This could simply be a bug in ntopng’s active discovery code. Compared to the main ntopng code, it’s rather immature and little used. I do not recommend it.

        ? 1 Reply Last reply Reply Quote 1
        • stephenw10S Offline
          stephenw10 Netgate Administrator
          last edited by

          Do you have any custom outbound NAT rules on OPT?

          ? 1 Reply Last reply Reply Quote 0
          • ? Offline
            A Former User @dennypage
            last edited by

            This post is deleted!
            dennypageD 1 Reply Last reply Reply Quote 0
            • ? Offline
              A Former User @stephenw10
              last edited by

              This post is deleted!
              1 Reply Last reply Reply Quote 0
              • ? Offline
                A Former User
                last edited by

                This post is deleted!
                patient0P johnpozJ dennypageD 4 Replies Last reply Reply Quote 0
                • dennypageD Offline
                  dennypage @Guest
                  last edited by

                  @JohnUtiu said in SG-1100 - Ntopng Network Discovery finds strange 15.xxx addresses on disconnected OPT port:

                  Do you have any ideas about how a bug could result in a strange public ip addresses being sticked on the ip address of the interface?

                  The last two ntopng core dumps that were brought to my attention were memory corruption resulting from the use of active network discovery.

                  1 Reply Last reply Reply Quote 0
                  • patient0P Offline
                    patient0 @Guest
                    last edited by

                    @JohnUtiu said in SG-1100 - Ntopng Network Discovery finds strange 15.xxx addresses on disconnected OPT port:

                    WAN tcp 192.xxx.xxx.xxx:51949 -> 15.179.xxx.xxx:22 SYN_SENT:CLOSED 2 / 0 120 B / 0 B
                    WAN tcp 192.xxx.xxx.xxx:62155 -> 15.179.xxx.xxx:80 SYN_SENT:CLOSED 2 / 0 120 B / 0 B

                    According to ipinfo.io and the RIPE db the IP range 15.179.0.0 to 15.188.255.255 is part of Amazon Technologies Inc..

                    You got an Amazon device that calls home?

                    dennypageD ? 2 Replies Last reply Reply Quote 0
                    • johnpozJ Offline
                      johnpoz LAYER 8 Global Moderator @Guest
                      last edited by

                      @JohnUtiu said in SG-1100 - Ntopng Network Discovery finds strange 15.xxx addresses on disconnected OPT port:

                      WAN tcp 192.xxx.xxx.xxx:51949 -> 15.179.xxx.xxx:22 SYN_SENT:CLOSED 2 / 0 120 B / 0 B

                      If that is not your address, why are you hiding it? Like me hiding that making a connection to 8.8.x.x ???

                      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

                      1 Reply Last reply Reply Quote 1
                      • dennypageD Offline
                        dennypage @patient0
                        last edited by

                        @patient0 said in SG-1100 - Ntopng Network Discovery finds strange 15.xxx addresses on disconnected OPT port:

                        According to ipinfo.io and the RIPE db the IP range 15.179.0.0 to 15.188.255.255 is part of Amazon Technologies Inc..

                        You got an Amazon device that calls home?

                        More likely it's ntopng itself.

                        johnpozJ 1 Reply Last reply Reply Quote 0
                        • dennypageD Offline
                          dennypage @Guest
                          last edited by

                          @JohnUtiu said in SG-1100 - Ntopng Network Discovery finds strange 15.xxx addresses on disconnected OPT port:

                          It seems that every time I run network discovery on ntopng, a connection is being opened FROM my WAN interface TO exactly the same 15.xxx ip address that is being sticked on the OPT interface.

                          WAN tcp 192.xxx.xxx.xxx:51949 -> 15.179.xxx.xxx:22 SYN_SENT:CLOSED 2 / 0 120 B / 0 B
                          WAN tcp 192.xxx.xxx.xxx:62155 -> 15.179.xxx.xxx:80 SYN_SENT:CLOSED 2 / 0 120 B / 0 B

                          It's trying to connect to port 20 and 80 on this address.

                          Where are you geographically?

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

                            @dennypage said in SG-1100 - Ntopng Network Discovery finds strange 15.xxx addresses on disconnected OPT port:

                            More likely it's ntopng itself.

                            Yeah and if some public internet IP wasn't obfuscated we could prob look up its PTR and glean some insight to what is is..

                            You want help identifying what some odd public IP is, which you know isn't your actual IP, or the IP of your gateway from your isp - why are you hiding it.. Why are you hiding your rfc1918 IP as well?

                            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

                            1 Reply Last reply Reply Quote 0
                            • dennypageD Offline
                              dennypage @Guest
                              last edited by

                              @JohnUtiu said in SG-1100 - Ntopng Network Discovery finds strange 15.xxx addresses on disconnected OPT port:

                              WAN tcp 192.xxx.xxx.xxx:51949 -> 15.179.xxx.xxx:22 SYN_SENT:CLOSED 2 / 0 120 B / 0 B
                              WAN tcp 192.xxx.xxx.xxx:62155 -> 15.179.xxx.xxx:80 SYN_SENT:CLOSED 2 / 0 120 B / 0 B

                              It's trying to connect to port 20 and 80 on this address.

                              Btw, assume that you meant port 22 rather than port 20. This is ssh.

                              Some of the (really bad) things ntopng does when active discovery is enabled is to run ssh, snmp and http probes against hosts it finds in the network.

                              ? 1 Reply Last reply Reply Quote 0
                              • ? Offline
                                A Former User @dennypage
                                last edited by

                                This post is deleted!
                                1 Reply Last reply Reply Quote 0
                                • ? Offline
                                  A Former User @patient0
                                  last edited by

                                  This post is deleted!
                                  1 Reply Last reply Reply Quote 0
                                  • S Offline
                                    SteveITS Galactic Empire @Guest
                                    last edited by

                                    @JohnUtiu said in SG-1100 - Ntopng Network Discovery finds strange 15.xxx addresses on disconnected OPT port:

                                    ntopng ... on a Netgate 1100

                                    FYI Netgate marks that package as "requires SSD" due to the usually high I/O generated:
                                    https://www.netgate.com/supported-pfsense-plus-packages

                                    You might check https://docs.netgate.com/pfsense/en/latest/troubleshooting/disk-lifetime.html.

                                    Only install packages for your version, or risk breaking it. Select your branch in System/Update/Update Settings.
                                    When upgrading, allow 10-15 minutes to reboot, or more depending on packages, CPU, and/or disk speed.
                                    Upvote 👍 helpful posts!

                                    ? 1 Reply Last reply Reply Quote 1
                                    • ? Offline
                                      A Former User @SteveITS
                                      last edited by

                                      This post is deleted!
                                      1 Reply Last reply Reply Quote 0
                                      • ? Offline
                                        A Former User @Guest
                                        last edited by

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