How to see what machines are on your network

This is part of the Semicolon&Sons Code Diary - consisting of lessons learned on the job. You're in the networking category.

Last Updated: 2021-05-16

How to see what machines are on your network?

$ nmap 192.168.100.0/24

Starting Nmap 7.80 ( https://nmap.org ) at 2019-08-29 04:44 CEST

# These are the entries for my router
Nmap scan report for easy.box (192.168.2.1)
Host is up (0.022s latency).
Not shown: 996 closed ports
PORT    STATE    SERVICE
22/tcp  filtered ssh
53/tcp  open     domain
80/tcp  open     http
443/tcp open     https

# These are the entries for my laptop
Nmap scan report for computer-2C2E39.local (192.168.2.103)
Host is up (0.029s latency).
Not shown: 993 closed ports
PORT     STATE SERVICE
21/tcp   open  ftp
23/tcp   open  telnet
80/tcp   open  http
443/tcp  open  https
515/tcp  open  printer
631/tcp  open  ipp
9100/tcp open  jetdirect

# These are the entries for my WIFI extender
Nmap scan report for fritz.repeater (192.168.2.113)
Host is up (0.0063s latency).
Not shown: 997 closed ports
PORT    STATE SERVICE
53/tcp  open  domain
80/tcp  open  http
443/tcp open  https

# These are the entries for my phone
Nmap scan report for Honor_10-ababababababababa.local (192.168.2.116)
Host is up (0.011s latency).
Not shown: 990 closed ports
PORT     STATE    SERVICE
53/tcp   filtered domain
110/tcp  filtered pop3
111/tcp  filtered rpcbind
443/tcp  filtered https
554/tcp  filtered rtsp
3306/tcp filtered mysql
3389/tcp filtered ms-wbt-server
5900/tcp filtered vnc
8080/tcp filtered http-proxy
8888/tcp filtered sun-answerbook