Category: Protocols & RF

Packet capture showing TCP SYN, SYN-ACK, ACK, and IP TTL

TCP/IP Handshake Explained: Transport-Layer Functions and TTL

Posted on 2026-07-03 by Sam Snider

See how the TCP three-way handshake works, what transport-layer fields do, and how IP TTL limits each packet’s life without being part of the TCP header.

Packet switching flow showing Layer 2 frames, IP next hops, and TCP or UDP ports

How Packet Switching Works at Layer 2 and Well-Known Ports

Posted on 2026-07-02 by Sam Snider

See how packet switching works from app data to Ethernet frames, through Layer 2 MAC checks, then across IP next hops. Learn where TCP and UDP ports identify services.

Windows RDP listener configured on port 3389

RDC Port 3389: Find, Change, and Test Windows Remote Desktop

Posted on 2026-06-30 by Sam Snider

The default RDC port is 3389. Find the listener, connect with host:port syntax, change the setting, update firewall and NAT rules, and verify the service.

IPv4 packet header with ICMP type and code details

ICMP Types in the IPv4 Packet Header: A Field-by-Field Guide

Posted on 2026-06-20 by Sam Snider

Learn how to read the IPv4 packet header, spot ICMP using the protocol field, and decode echo, unreachable, time exceeded, and redirect messages with examples.

Router forwarding an RDP connection to a PC

Port Forwarding to a PC With a Custom RDP Listening Port

Posted on 2026-06-15 by Sam Snider

Learn port forwarding to a PC with an RDP listening port: update the RDP port in Regedit, restart the service, match firewall and router rules, then test local, LAN, gateway, and external access.

Network switch and laptop showing MAC identification, packet-loss testing, and CRC diagnostics

How to Identify a Device by MAC Address Online and Test Network Faults

Posted on 2026-06-09 by Sam Snider

Learn how to identify a device by MAC address online: use local MAC tables, ARP, DHCP, and vendor data—not a public lookup—then run an internet packet loss test and read CRC checksum errors.