Hack the Route Start free Open app Labs / Speaking Protocols
Road 2 of 11
Speaking Protocols
TCP, UDP and DNS, then the protocols programs speak on top: the web and its certificates, mail, files, time and the office.
Start this road, freeTCP, UDP & DNS
Ports, connections and names turned into addresses.
- 01 TCP and UDP: ports, connections and datagrams TCP vs UDP: see ports, the TCP handshake and teardown, and no-promises datagrams. Free
- 02 The DNS tree: how a name is found Follow a resolver down the DNS hierarchy, from the root to an answer. Pro
- 03 DNS zones, zone transfers and encrypted DNS Serve a zone, copy it by DNS zone transfer, then query over DoT and DoH. Pro
HTTP, TLS & mail
The web, its security and versions, and mail, up close.
- 01 HTTP up close: requests, answers and connections Type HTTP requests by hand and read every line of the answers. Pro
- 02 TLS certificates: chains, trust and what breaks them Read a certificate chain, see what breaks it, and trust a self-signed one. Pro
- 03 HTTP/1.1, HTTP/2 and HTTP/3 Compare HTTP versions: ALPN picks one, HTTP/2 shares a connection, HTTP/3 rides QUIC. Pro
- 04 The path of an email How email works: send one by hand over SMTP and follow it between servers. Pro
Time & office: NTP, files, FTP & PTP
Keeping time, and the office's files, desktops and calls.
- 01 NTP: keeping clocks right, and what a wrong one breaks Set clocks with NTP, outvote a wrong one, and watch a bad clock break TLS. Pro
- 02 The office LAN's own protocols: files, desktops and calls Watch file sharing, remote desktop and a VoIP call on an office LAN's wire. Pro
- 03 FTP: two channels, active and passive Move files over FTP: active, passive, and why only passive mode crosses NAT. Pro
- 04 PTP and NTS: time that is precise, and time that is proven Sync a clock to microseconds with PTP, then authenticate time with NTS. Pro