How IPv4 works
Each IPv4 packet includes a source address and destination address. Routers inspect the destination, consult their routing tables and forward the packet toward the matching network. DNS usually handles the earlier step of translating a domain such as example.com into an address.
An IPv4 address contains four decimal numbers from 0 to 255. For example, 203.0.113.42 represents four 8-bit values, giving 32 bits in total. A prefix such as 203.0.113.0/24 means the first 24 bits identify the subnet and the remaining bits distinguish addresses within it.
The 32-bit format provides 4,294,967,296 possible addresses, but reserved ranges reduce the number available for public use. NAT helps conserve public addresses by letting several devices use private addresses behind one public IPv4 address.
IPv4 vs IPv6
| IPv4 | IPv6 | |
|---|---|---|
| Address length | 32 bits | 128 bits |
| Notation | Four decimal numbers | Colon-separated hexadecimal |
| Address supply | Limited and largely allocated | Vast address space |
| Typical operation | NAT is common | Often deployed in dual stack |
IPv6 was created mainly to provide far more addresses. The two versions aren’t directly interchangeable, so networks often run both through dual-stack configurations. DNS can return an IPv4 A record, an IPv6 AAAA record or both.
How IPv4 relates to proxies
A proxy server can accept connections, make outgoing connections or do both over IPv4. When it uses an IPv4 exit, the destination receives the connection from the proxy’s public IPv4 address rather than directly from your device.
“IPv4 proxy” only describes the address family. It doesn’t say whether the address is residential or datacenter-based, dedicated or shared, or static or rotating. Websites may evaluate the address’s network owner, location, reputation and request rate.
Changing the visible IPv4 address doesn’t change cookies, HTTP headers or browser fingerprints. It also doesn’t cover traffic that bypasses the proxy, and a transparent proxy may disclose the original address in an HTTP header.
FAQ
Is IPv4 the same as an IP address?
No. IPv4 is one version of the Internet Protocol and its address format. An IP address can be either an IPv4 address or an IPv6 address.
Are all IPv4 addresses public?
No. Some ranges are reserved for private networks, loopback, link-local communication, multicast and documentation. Only globally routable addresses can be reached directly across the public internet.
Does an IPv4 proxy hide my real IP?
Yes, at the network layer for traffic correctly sent through a nontransparent proxy. Connections that bypass the proxy can still expose your address, while cookies and fingerprints can correlate your activity without revealing it.