Edit Download this page as a PDF Copy page Copy page as Markdown for LLMs Open in ChatGPT Ask ChatGPT about this page Open in Claude Ask Claude about this page Fundamentals of the Internet Edit Download this page as a PDF Copy page Copy page as Markdown for LLMs Open in ChatGPT Ask ChatGPT about this page Open in Claude Ask Claude about this page DNS IP Address, Ports, Components of a domain A/CNAME/MX records ISPs Routers Introduction Introduction Last updated 7 months ago