The 128-bit successor to IPv4 and the protocol every modern network is migrating toward. Articles tagged IPv6 cover address format and types, the simplified header, Neighbor Discovery, SLAAC autoconfiguration, and Cisco IOS XE configuration.
IPv6 host addressing is where a lot of otherwise competent engineers quietly lose confidence, because there are three mechanisms that can all be running at once, they interact through two obscure flag bits in a router advertisement, and a host
This is the hands-on half of our OSPFv3 coverage: a complete dual-stack configuration on Cisco IOS XE, from ipv6 unicast-routing to verified end-to-end reachability, with every capture from a live CML lab. If you want
OSPFv3 is not "OSPF with longer addresses". It is a redesign of the protocol machinery that happens to have shipped alongside IPv6, and with address families (RFC 5838) it can carry IPv4 routes too, which surprises almost everyone
The IPv6 header byte by byte: 40 bytes fixed, 8 fields, extension headers, Next Header chaining, comparison to IPv4, and what it looks like in Wireshark.
IPv6 configuration on Cisco IOS XE: enabling IPv6, static and SLAAC addresses, RA options, OSPFv3, BGP for IPv6, EIGRP for IPv6, VRRPv3, dual-stack, and first-hop security.
The six IPv6 address types: global unicast, link-local, ULA, multicast, anycast, and special. Prefixes, scope, when to use which, and design implications.
IPv4 vs IPv6 in 2026. Header differences, ARP vs Neighbor Discovery, SLAAC vs DHCP, NAT vs end-to-end, and dual-stack as the migration reality.
IPv6 addresses are 128 bits as eight groups of four hex digits. The two compression rules, prefix notation, EUI-64 interface IDs, special addresses, and worked examples.