The countdown
Every proxy is ultimately an IP address with a story. Here are ten facts about those addresses that tend to surprise people, even people who buy proxies for a living.
10. Your home network uses addresses that do not exist on the internet
Addresses like 192.168.1.20 and 10.0.0.5 are reserved for private networks by RFC 1918. Millions of homes use exactly the same ones, which is fine, because they never leave the router. See public IP addresses.
9. 127.0.0.1 always means "this computer"
The whole 127.0.0.0/8 block, over 16 million addresses, is reserved for a machine talking to itself. It is why "there's no place like 127.0.0.1" is a programmer joke.
8. IP location is a guess
Geolocation databases are usually right about the country and often wrong about the city, especially for mobile IPs. Two databases can place the same IP in different states. See IP geolocation.
7. Your phone probably shares its public IP with strangers
Carriers put hundreds or thousands of phones behind one public IPv4 address using CGNAT. That is exactly why websites hesitate to ban mobile IPs. See CGNAT.
Proxy tip: A practical next step is to run a few requests through a commercial pool and watch what changes. Geonode supports HTTP, HTTPS and SOCKS5 and lets you switch between rotating and sticky sessions from the same endpoint. We walk through it in our Geonode proxies guide.
6. Some companies got 16.7 million addresses at once
In the early internet, organisations received whole /8 blocks. Apple still holds 17.0.0.0/8, and the US Department of Defense holds several. MIT held 18.0.0.0/8 and later sold millions of those addresses.
5. Addresses have a price tag
Because IPv4 is scarce, addresses are bought and sold through registry-approved transfers, typically for tens of dollars each. That cost is baked into every IPv4 proxy you rent. See cheap proxies.
4. The world ran out of IPv4 in 2011
IANA handed out its last free /8 blocks to the regional registries in February 2011. APNIC ran dry in Asia Pacific that April, and RIPE NCC in Europe in November 2019.
3. IPv6 has about 340 undecillion addresses
That is 2^128, roughly 3.4 × 10^38. A single home is typically given a /64, which alone holds 18.4 quintillion addresses, exactly the size of the entire IPv4 internet squared. See IPv6 proxies.
Budget tip: For jobs where a fixed IP list is enough, Webshare is one of the cheapest options: shared datacenter proxies are sold by the IP, and static residential (ISP) proxies cost well under a dollar per IP per month at the time of writing. More in Webshare's free proxy plan.
2. Five registries run the world's address book
AFRINIC, APNIC, ARIN, LACNIC and RIPE NCC allocate addresses for their regions, under IANA. Their records are the starting point for every geolocation database and every ASN lookup. See ASNs.
1. IPv4 has only 4,294,967,296 addresses
That is 2^32, set in RFC 791 in 1981, when nobody imagined phones, TVs and doorbells all wanting one. Everything else on this list, from CGNAT to address prices to proxy pricing, follows from that one number.
Residential tip: If you want to try this on an ethically sourced residential pool, Rayobyte offers a free trial with no credit card, then pay-as-you-go traffic from $3.50 per GB that drops to $0.70 per GB at 1 TB. See choosing the right Rayobyte product.
Learn more
- IPv4 vs IPv6 proxies
- What is CGNAT?
- What do /24 and /64 mean?
- Top 10 proxy terms to know
- RFC 791, the 1981 IPv4 specification
- RFC 1918, private address ranges
- List of assigned /8 IPv4 blocks
- RIPE NCC on IPv4 run-out
Sources and further reading
Independent references that back up the points above, from standards bodies, governments, universities and non-profits. They open in a new tab.
- RFC 791: Internet Protocol (IPv4) (IETF / RFC Editor): The 1981 specification of IPv4, whose 32-bit addresses most proxies still use.
- RFC 1918: Address Allocation for Private Internets (IETF / RFC Editor): Defines the private address ranges that home routers hide behind one public IP.
- List of assigned /8 IPv4 address blocks (Wikipedia): Who was handed the original giant /8 IPv4 blocks of 16.7 million addresses each.
- IPv4 Run-out (RIPE NCC): RIPE NCC's record of running out of IPv4 addresses in Europe and the Middle East.
- Number Resources (IANA): How IANA hands IP address blocks to the regional internet registries.
- RFC 6598: Shared Address Space for Carrier-Grade NAT (IETF / RFC Editor): Explains the shared address space carriers use for CGNAT, the reason many phones share one mobile IP.
Editorial note: Proxy providers change their pools, features and prices often, so treat any figures here as typical ranges at the time of writing and confirm current terms with the provider before you buy.