we’re out of IP Addresses….but this saved us (Private IP Addresses)

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About this video

Part of the ‘You Suck at Subnetting’ series, this explains why the internet did not run out of usable addresses in the 1990s despite IPv4 having only about 4.3 billion addresses (2 to the 32nd power). The fix described is RFC 1918, which carved private ranges out of the Class A, B and C ranges — the most familiar for home users being 192.168.x.x — that are not unique and not routable on the public internet, so millions of homes and businesses can reuse the same addresses internally. The other half of the fix is Network Address Translation, performed by the home router: an ISP gives the household one public IP, the router gives devices private IPs, translates outbound requests to that one public address, and forwards replies back to the correct internal device. The video closes by noting IPv4 still ran out, introducing IPv6 (2 to the 128th power, enough for every device to have a public address, already used by many mobile carriers), while arguing IPv4 and subnetting remain essential to learn. Includes sponsor segments for Dashlane and Boson practice exams.

Key takeaways

Private IP addresses from RFC 1918 are not unique and are not publicly routable, which lets millions of networks reuse the same ranges internally
NAT on the router lets an entire home or business share a single ISP-assigned public IP address for all internet traffic
You can contrast the two addresses yourself: ipconfig shows your device’s private IP, while searching ‘what is my IP’ shows the public IP the internet sees
IPv4 provides about 4.3 billion addresses (2^32); IPv6 expands this to 2^128 and is already used for many phones on cellular networks
Private addressing plus NAT is presented as the standard pattern for nearly every home and business network, not just a home-router trick

Episode details: published April 18, 2022 · 15:02 long. Summary written by Self Growth Videos from the episode itself. Business results and any income figures mentioned are NetworkChuck’s own claims, shared for education — they are not typical or guaranteed.

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