IPv6 Explained: How It Works and What to Look For
IPv6 supplies 128-bit addressing and a streamlined base packet header.
Published by Protocol Explorer · Reviewed
How IPv6 works
An IPv6 packet contains source and destination addresses, a next-header value and a hop limit. Additional extension headers can carry further information.
What to look for in an exchange
Follow the Next Header chain to identify the transport protocol. Neighbor discovery uses ICMPv6 for local-link functions; it is specified separately from the base IPv6 header.
Follow an example step by step
- Locate the 128-bit source and destination addresses in the base header.
- Follow Next Header values through any extension headers to the upper-layer protocol.
- Compare Hop Limit values across hops and examine ICMPv6 messages when diagnosing the path.
Common interpretation mistake
An IPv6 address can be link-local or global; its scope changes where it is meaningful.
Key point to remember
Neighbor discovery is part of ICMPv6 and should not be confused with DNS name resolution.
Explore the protocol
The IPv6 overview is free without an account. Its full interactive lesson is included in Protocol Explorer Pro, a one-time $4.99 purchase; an account is required to buy Pro and restore the licence across devices.
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Specification
Read the primary specification for IPv6 for the authoritative protocol details. The interactive scenario is a simplified teaching model, not a capture of your network.
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