UPDATE 10/4 6:47 EDT

I have been going through all the comments. THANKS!!! I did not know about the techniques listed, so they are extremely helpful. Sorry for the slow update. As I mentioned below, I got behind with this yesterday so work cut into my evening.

I ran a port scan. The first syntax, -p, brought no joy. The nmap software itself suggested changing to -Pn. That brought an interesting response:

nmap -Pn 1-9999 <Local IP Addr>

Starting Nmap 7.93 ( https://nmap.org ) at 2024-10-04 11:44 BST

Failed to resolve “1-9999”. Nmap scan report for <Local IP Address> Host is up (0.070s latency). All 1000 scanned ports on 192.168.0.46 are in ignored states. Not shown: 990 filtered tcp ports (no-response), 10 filtered tcp ports (host-unreach) Nmap done: 1 IP address (1 host up) scanned in 6.03 seconds Just to be absolutely sure, I turned off my work computer (the only windows box on my network) and reran the same syntax with the same results.

As I read this, there is definitely something on my network running windows that is not showing up on the DHCP.

UPDATE 10/6

I am working through all these suggestions. I am sorry for the slow responses, but I have my hands full with family weekend. I will post more next tomorrow. But I did do one thing that has me scratching my head and wondering if this may be a wild goose chase.

I ran the nmap again per below with a completely fictional IP address within my normal range. It gave the exact same results:

nmap -A -T4 -p- -Pn <Fictional IP>

Starting Nmap 7.93 ( https://nmap.org ) at 2024-10-05 13:36 BST Nmap scan report for <Fictional IP>

Host is up (0.054s latency).

All 65535 scanned ports on <Fictional IP> are in ignored states.

Not shown: 65525 filtered tcp ports (no-response), 10 filtered tcp ports (host-unreach)

Service detection performed. Please report any incorrect results at https://nmap.org/submit/ .

Nmap done: 1 IP address (1 host up) scanned in 182.18 seconds

    • RestrictedAccount@lemmy.worldOP
      0·
      3 months ago

      I lost my entire morning to this yesterday. I had to work late to catch up. There are some good ideas in here I’m starting on now.

  • fmstrat@lemmy.nowsci.comEnglish
    0·
    3 months ago

    Others haven’t suggested this yet, but a single device, like your laptop, even with one connection, can have two IPs.

  • rtxn@lemmy.worldEnglish
    0·
    3 months ago

    The default home page for Microsoft IIS, the web server built into Windows Server (and probably some desktop builds too).

  • peopleproblems@lemmy.world
    0·
    3 months ago

    Depending on your router, it could have a docker setup with Windows on it. I’ve seen some strange shit on cheap routers with far too much processing power and storage.

  • Seasm0ke@lemmy.world
    0·
    3 months ago

    Following, I want to know what god awful iot device this is. Refrigerator? Toaster oven? Vibrating dildo? The suspense is killing me

        • froh42@lemmy.world
          0·
          3 months ago

          I have a Bluetooth controlled vibrator. Reverse engineered the app (which has a chat function) and it has a blacklist of words (mainly Chinese) you’re not allowed to text using the app.

          I did not check if your horny chat gets copied to Chinese spy agencies, but I suspect that will be done on the server.

        • DokPsy@lemmy.world
          0·
          3 months ago

          Hey, I’m not normally one to judge but it seems like a bad idea to call yourself spyware. Either you’re going to blow your cover or it’s just negative self talk.

  • OfficerBribe@lemm.ee
    0·
    3 months ago

    Besides the MAC lookup suggestion, have you tried to simply find hostname in local DNS by reverse IP lookup, maybe that would shed some light.

    Not sure if there is anything useful, but in browser just check site source, maybe there is something useful there that could help with identification. Does site have certificate? It might include info that would help with identification. Do the standard browser network trace via dev tools F12, maybe something useful appears there.

    In nmap you can attempt to guess OS, try that. Additionally it might be possible to get hostname as well.

    And have you checked your router to see if this connection is connected to your Wi-Fi AP or Ethernet to narrow things down? If it is not possible to determine this from router, simply connect your main PC to Ethernet, disable AP in router settings and check if IIS site is still up. If it is not, enable AP again, does it come back early or it takes some time?

    Lastly, if it still is a mystery, start powering off devices one by one to find the source. Based on comments it seems you have multiple devices, but I assume it would not take that long?

  • SlothMama@lemmy.world
    0·
    3 months ago

    Get the MAC address from the ARP table, and look up the OIN, should help you determine if it’s virtual or physical, and if physical the type of NIC it’s using.

  • f4f4f4f4f4f4f4f4@sopuli.xyzEnglish
    0·
    3 months ago

    nmap’s seeing the 1-9999 as the next argument (expecting an IP address). In -Pn, the n is a placeholder for the port numbers you want to scan, so you want -P1-9999

    • RestrictedAccount@lemmy.worldOP
      0·
      3 months ago

      This is interesting. I had to modify it to nmap -A -T4 -p- -Pn <IP>.

      It said the host is up with 0.077 seconds of latency. All 64k ports were scanned with 7 filtered tcp ports (host-unreachable) and the rest (no-response).

      • deltapi@lemmy.world
        0·
        3 months ago

        What’s weird about this is that it should be getting a response from IIS like you showed us in the screenshot.

      • mrbaby@lemmy.world
        0·
        3 months ago

        77ms of latency is pretty slow. Based off that I’d assume (but not rule out) that it’s not: on the machine you used to run nmap, not on ethernet, probably wifi with a shitty connection

        So, some really dumb, likely irrelevant, questions that might spark an idea:

        • Do you see anything weird connected in the wifi client list? (You said it wasn’t given a dhcp lease, but it would still show as a wireless client even if it were static)

        • Are you running a VPN server or using VPN to bridge any networks?

        • You said you’re running dual WAN, are those configured properly and not leaking random internet shit into your LAN?

        • Do you have anything that might be running some kind of out-of-band management system like DRAC on a dell server?

        • What’s your IoT situation?

        • Do you have an on-site NVR for security cams?

        • Did you find the mac? If so what are the first 3 octets? Even if the vendor can’t be found, there’s always the chance some crazy ubernerd is going to recognize it. (If it’s 00:d0:2c or 44:d9:e7 I got ya covered)

        Again, most of those are probably irrelevant, but throwing the thoughts out there :)

  • fubarx@lemmy.ml
    0·
    3 months ago

    There was an appliance where the wifi chip was at the end of the power cable, embedded inside the plug. From the outside, you couldn’t really tell. It was there so radiation inside the box couldn’t affect the wireless signal as much.

    I can imagine some genius thinking it’s a good idea to run a server from inside a cable or a connected home appliance.

  • Kelly@lemmy.worldEnglish
    0·
    3 months ago

    Home network or corporate?

    Its a windows server, if you are using widows too you can try establishing a RDP connection with Remote Desktop Connection.

      • Kelly@lemmy.worldEnglish
        0·
        3 months ago

        Eyeballing the login screen may give some insight, you’re right that its probably unwise to try real creds if you don’t recognize the server.

    • RestrictedAccount@lemmy.worldOP
      0·
      3 months ago

      It is a home network. Configured by someone who understands the basics, but is mostly following recipeies rather than having deep knowledge.