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.
Any device on an IPv6 segment can send a Router Advertisement and reconfigure every host's default gateway. This post configures RA Guard and DHCPv6 Guard, then floods rogue RAs to prove the switch blocks them.
SLAAC, stateless DHCPv6, and stateful DHCPv6 can all run at once, arbitrated by the M and O flags. This article untangles all three, then builds a stateful server with a relay on Cisco IOS XE and a real Linux client taking a lease.
A complete dual-stack OSPFv3 configuration on Cisco IOS XE, from ipv6 unicast-routing to verified end-to-end reachability, with every capture taken from a live CML lab.
OSPFv3 is a protocol redesign, not OSPF with longer addresses, and with address families it carries IPv4 too. See what changed from OSPFv2, what stayed identical, and what it looks like on the wire in a live Cisco IOS XE lab.
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.