Ipv6

IPv6 IPv6 was designed to solve IPv4 address exhaustion while simplifying the protocol. The header is fixed-length and streamlined, broadcast is eliminated in favor of multicast, and address configuration can be fully automatic. For service providers, the most exam-relevant areas are address types, NDP, autoconfiguration, and how routing protocols (OSPF, IS-IS) extend to support IPv6. IPv4 vs IPv6 Key Differences Feature IPv4 IPv6 Address size 32 bits 128 bits Header size Variable (20–60 bytes) Fixed 40 bytes Header checksum Yes No (relies on L4) Fragmentation Routers and source Source only Broadcast Yes No — replaced by multicast Address resolution ARP NDP (ICMPv6) Autoconfiguration DHCP only SLAAC + DHCPv6 IPsec Optional Built into extension header framework IPv6 Header The base IPv6 header is always exactly 40 bytes. It is simpler than IPv4 — no checksum, no options field, and no fragmentation fields (those are handled by extension headers when needed). ...