### ping "are these computers even connected?" ### curl make any HTTP request you want ### httpie like curl but easier ("http get") ### wget download files ### tc on a linux router, slow down your brother's internet (and much more) ### dig/nslookup what's the IP for that domain? (DNS query) ### whois is this domain registered? ### ssh secure shell 💙 ### scp copy files over a SSH connection ### rsync copy only changed files (works over SSH) ### ngrep grep for your network ### tcpdump "show me all packets on Port 80!" ### wireshark look at those packets in a GUI ### tshark command line super powerful packet analysis ### tcpflow capture & assemble TCP streams ### ifconfig "what's my IP address?" ### route view & change the route table ### ip replaces ifconfig, route, and more! ### arp see your ARP table ### mitmproxy spy on SSL connections your programs are making ### nmap in ur network scanning ur ports ### zenmap GUI for nmap ### p0f identify OS of hosts connecting to you ### openvpn a VPN ### wireguard a newer VPN ### nc netcat! make TCP connections manually ### socat proxy a TCP socket to a unix domain socket + LOTS MORE ### telnet like SSH but insecure ### ftp/sftp copy files. sftp does it over SSH. ### netstat/ss/sof/fuser "what ports are servers using?" ### iptables set up firewalls and NAT! ### nftables new version of iptables ### hping3 construct any TCP packet you want ### traceroute/mtr what servers are on the way to that server? ###