Interfaces & IP
ipconfig /all # or ip a; ip route; resolvectl status
Who’s on my LAN
arp -a # or nmap -sn 192.168.1.0/24
Reachability
ping 8.8.8.8 -n 10 tracert 8.8.8.8 # or ping -c 10 1.1.1.1; traceroute 1.1.1.1
DNS sanity
nslookup example.com # or dig +trace example.com
Ports
netstat -ano | findstr LISTENING # or ss -tulpen
Logs you actually read
- Windows: Event Viewer → Windows Logs → System → filter by Tcpip, Dhcp.
- Linux: journalctl -u NetworkManager --since "-1h"
- Router: syslog export; look for DHCP conflicts, deauths.