/ˌaɪ-ˌpiː-viː-ˈsɪks/
n. “The internet’s answer to running out of room.”
IPv6, short for Internet Protocol version 6, is the successor to IPv4 and was designed to solve the problem of IP address exhaustion while improving efficiency, scalability, and modern networking capabilities. It defines how devices are addressed and how data packets are routed across networks, just like IPv4, but on a vastly larger scale.
An IPv6 address is 128 bits long, compared to IPv4’s 32 bits. This allows for an astronomically large number of unique addresses — enough to assign a unique IP to virtually every device on the planet, and then some. IPv6 addresses are written in hexadecimal and separated by colons, rather than dots.
A typical IPv6 address looks like this:
2001:0db8:85a3:0000:0000:8a2e:0370:7334To make addresses easier to read, IPv6 allows simplifications such as removing leading zeros and compressing consecutive zero blocks:
2001:db8:85a3::8a2e:370:7334Key characteristics of IPv6 include:
- 128-bit Address Space: Provides approximately 3.4×10³⁸ unique addresses.
- No Mandatory NAT: Designed so devices can have globally unique addresses without relying on NAT or PAT.
- Simplified Headers: More efficient packet processing for routers.
- Built-in Security: IPsec support is standardized as part of the protocol.
- Improved Auto-Configuration: Supports stateless address auto-configuration (SLAAC).
Conceptually, IPv6 replaces the cramped apartment building of IPv4 with a near-infinite universe of addresses, allowing direct, end-to-end connectivity without port juggling or address reuse.
In essence, IPv6 is the long-term foundation of internet growth — engineered for scale, resilience, and a future where everything, from servers to sensors, can have its own globally unique identity.