ZenMap (A GUI for nmap) works good for discovering devices on specified subnet ranges. https://nmap.org/zenmap/
Spiceworks has an inventory scanner and you can use that to make a "network map" of sorts... But it's based on flash and garbage UI. I don't think it's been updated for years.
So which IP are you scanning, your public IP (assigned from your ISP) or your private IP (handed out by your home router)? The public IP is probably hitting your home router and not giving us correct information. Go to a command prompt and type ipconfg (on windows) or ifconfig (mac / linux). The IP address it gives there is the one you want to scan.
In this case - you own all the hardware involved and are scanning your own services so legally this is fine. I am not a lawyer but I've heard port scanning referred legally to jiggling a door handle to see if a door is unlocked.
I would recommend using Nmap or the GUI Zenmap. https://nmap.org/zenmap/
More info on the legal considerations when scanning things you don't own https://nmap.org/book/legal-issues.html
1: Katso sopimuksesta mikä on kielletty
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Porttiskannaus on hyvä menetelmä aiheuttaa harmaita hiuksia operaattoreille, koska se laukaisee hälytyksiä verkkovalvonnassa. Suoraan yhdistetty verkkohyökkäyksiin, niin jos alat skannata www.eduskunta.fi, niin poliisi on todennäköisesti aika äkkiä kyselemässä että mitä teet. Kunhan sinulla on lupa koneen omistajalta, niin voit sanoa että teet tietoturvatarkistuksia. En aio lähteä sen enempää avaamaan aihetta sen enempää koska se on todella laaja, mutta alkuun pääsee ottamalla ohjelman alas, ja skannaamalla vaikka omaa konetta alkuun (IP: 127.0.0.1)
Sivustolla on myös kattavat ohjeet, millä pääsee alkuun. Ja googlestakin löytää matskua hakusanoilla "port scanning guide tai tutorial" ja "nmap guide" yms.
Can you set your router to automatically be assigned an IP address instead of manually selecting one? If you need to manually set it, then you need to know the address the ISP uses as it looks like that they have a router installed and that's what you are connecting to. If they use 192.168.1.1 then you set your router to use 192.168.1.X where the X is an available address on the network. The new set IP address will be how you log into the router from now on.
If it's automatically assigned one, it can be a pain to find it's IP address later in order to log into the control pane. I use Netscan Portable which will list every device on the network (hopefully, some devices seem to hide from everything). There is also Zenmap which does the same thing.
If you connect the wall Ethernet port to a LAN port instead of WAN, then a lot of routers will automatically go into Bridge AP mode.
If you have a device with Ehternet, you can plug that into the wall and check the IP range. If that's a Windows PC, open command prompt and use the command "ipconfig". Look at Default Gateway.
If you need any more help from here, then feel free to ask.
ZenMap might be helpful to you as a learning tool. It’s a GUI front end for nmap, you can set your scan somewhat more intuitively while learning with the GUI, but it will show you the full command line being piped to the nmap binary.
I don't know how capable your router is, but i would start by looking at the router logs. Look at the DHCP reservations to see if you can identify unknown devices. I would then scan my subnet to try and identify unknown devices. You can use zenmap for the scanning.
Here is a quick nmap command to check SSL Cipher suites and Cert status. It also checks SQL, and RDP ciphers.
Grab Zenmap (NMap GUI) - Gives a letter grade similar to SSLLabs
namp -p T:443,1433,3389 --script ssl-cert,ssl-enum-ciphers <ip or hostnames space delimited>
When it notified you of a new connection, I'm assuming that was for WiFi right? If it told you an IP address, I would port scan that device to find out more about it. You can download the GUI to the NMAP port scanner for free: https://nmap.org/zenmap/
Once you find open ports, you could interrogate those for additional info. For instance, if you see port TCP/443 or TCP/80 open, you could navigate to it on a browser and see what's there. To navigate it would be https://<ip_address> and http://<ip_address>, respectively.
>I am not sure what service is running and not am I able to know who's PC/Server and which service it has running.
Have you tried nmap? Try $ nmap -v -A 192.168.0.5 (or whatever IP/hostname it is).
(Alternatively, there is a cross-platform GUI frontend called zenmap that does the same thing if that's more convenient for you)
If you paste the nmap output we could take a look.
INstall ZenMap (a Gui to nmap) on your laptop. From there you can initiate a scan of your local LAN: Your pi will show up with its IP
Alternatively: Check the config of your switch and see if there is a page where you can see attached devices.
I like nmap -- https://nmap.org/zenmap/ -- scans the environment and gives you details on everything within a particular subnet/network range. Will show things like OS, Ports open, Vendor of hardware.