Blog

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.

HSRP, VRRP, and GLBP all solve first-hop redundancy with different trade-offs. The side-by-side comparison, when each wins, failover times, and migration paths.

GLBP (Gateway Load Balancing Protocol) is Cisco's load-balancing FHRP. AVG, AVFs, three load balancing methods, configuration, and when GLBP is actually the right answer.