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

  • 9point6@lemmy.world
    0·
    3 months ago

    Have you recently installed visual studio or are doing any .NET development? It could possibly be a containerised version of IIS

    If you completely turn off your windows device and try to access the IP from another device does it still resolve?

      • 9point6@lemmy.world
        0·
        3 months ago

        Hmm

        I’d maybe try systematically turning any other devices off you think could potentially have the grunt to run windows server in a container or VM.

        Do you have a Mac/Linux machine handy? If you run arp -a in one terminal and ping the unusual IP in another, that should give you a corresponding MAC address for the device. You can then look up the Mac address and see if it gives you any more info about the device running it—it might not but you never know. You can use something like https://dnschecker.org/mac-lookup.php

        I guess next you could look at taking that MAC and blocking it in your router control panel and see if anything starts complaining

        • Agent641@lemmy.world
          0·
          3 months ago

          In addition, you might like to do a portscan on that IP address to see if any other ports reaveal something more interesting.

          You can run this in cmd prompt, I think, if nmap is available on your windows machine:

          nmap -p 1-9999 192.168.1.1

          IIS can only run on a windows OS, so it must be a windows physical machine or VM connected to your network.

          • RestrictedAccount@lemmy.worldOP
            0·
            3 months ago

            Thanks as you can tell, I’m not an expert in any of this.

            I will run this as you described.

            I did the nmap based on input from ChatGPT, it had me do a Ping base scan with nmap. It turned up nothing because that IP address did not return a Ping.

            This has me really curious.

            I’m concerned that the website I opened in Safari on my phone is bringing up a cache on my browser and is not actually live.

            I tried to open it from an iPad and it did not load. Iit still loads off my phone even though I have rebooted everything.

            • biscat@lemmy.world
              0·
              3 months ago

              In case it helps your troubleshooting, ICMP (ping) is typically disabled by default on Windows.

                • 0xD@infosec.pub
                  0·
                  3 months ago

                  Your command needs to look something like this:

                  nmap -Pn -sVC -p- (IP) -o scan

                  -Pn skips the availability check per ping

                  -sVC performs a version and a script scan so you get more information

                  -p- scans ALL ports

                  -o puts out a file called scan.nmap

                  If you want you can share that output afterwards for further info.

                  Edit: You can also try enumerating the directories on the server if you find no content. I can help you with that if you want.

        • thermal_shock@lemmy.worldEnglish
          0·
          3 months ago

          I guess next you could look at taking that MAC and blocking it in your router control panel and see if anything starts complaining

          I love the “see who screams” method, my coworkers do no. it’s usually instant.