Internet Protocol Version 8 (IPv8) is a managed network protocol suite that transforms how networks of every scale -- from home networks to the global internet -- are operated, secured, and monitored. Every manageable element in an IPv8 network is authorised via OAuth2 JWT tokens served from a local cache. Every service a device requires is delivered in a single DHCP8 lease response. Every packet transiting to the internet is validated at egress against a DNS8 lookup and a WHOIS8 registered active route. Network telemetry, authentication, name resolution, time synchronisation, access control, and translation are unified into a single coherent Zone Server platform. IPv4 is a proper subset of IPv8. An IPv8 address with the routing prefix field set to zero is an IPv4 address. No existing device, application, or network requires modification. The suite is 100% backward compatible. There is no flag day and no forced migration at any layer. IPv8 also resolves IPv4 address exhaustion. Each Autonomous System Number (ASN) holder receives 4,294,967,296 host addresses. The global routing table is structurally bounded at one entry per ASN. This document is one of the companion specifications: draft-thain-ipv8-00 Core protocol (this document) draft-thain-routing-protocols-00 BGP8, IBGP8, OSPF8, IS-IS8, CF draft-thain-rine-00 Regional Inter-Network Exchange draft-thain-zoneserver-00 Zone Server Architecture draft-thain-whois8-00 WHOIS8 Protocol draft-thain-netlog8-00 NetLog8 Protocol draft-thain-support8-00 ARP8, ICMPv8, Route8 draft-thain-ipv8-mib-00 IPv8 MIB and SNMPv8 draft-thain-wifi8-00 WiFi8 Protocol draft-thain-update8-00 Update8 and NIC Certification