What Is IPv6?

IPv6 Address Space

IPv6 Address Space priorities

IPv6 uses 128-bit addresses, providing 340 undecillion addresses compared to IPv4's 4.3 billion. This eliminates the need for NAT and allows every device to have a globally unique address.

IPv6 And Tunnel Brokers

IPv6 And Tunnel Brokers priorities

When your ISP does not provide native IPv6, a tunnel broker can encapsulate IPv6 traffic inside IPv4 to give you working IPv6 connectivity immediately.

IPv6 Features

IPv6 Features priorities

IPv6 includes built-in features like Stateless Address Autoconfiguration (SLAAC), Neighbor Discovery Protocol (NDP), mandatory IPsec support, and more efficient multicast routing.

IPv6 Tunnel Broker Overview

Network context and request workflow

IPv6 is the next-generation Internet Protocol designed to replace IPv4, which has been the foundation of online communication since the early 1980s. The primary driver behind IPv6 is the exhaustion of IPv4 address space: IPv4 uses 32-bit addresses, which limits the total number of connected devices to roughly 4.3 billion. In contrast, IPv6 uses 128-bit addresses, providing approximately 340 undecillion unique addresses. This is not merely a numerical upgrade but a fundamental change in how networks can be designed, assigned, and managed.

An IPv6 address is written as eight groups of four hexadecimal digits, separated by colons, such as 2001:db8:ffff:1:201:02ff:fe03:0405. Leading zeros in each group can be omitted, and one consecutive group of zeros can be replaced with a double colon (::). This compact notation makes addresses more manageable while maintaining sufficient uniqueness.

IPv6 eliminates the need for Network Address Translation (NAT), which became a common workaround in IPv4 networks to conserve address space. Without NAT, every device can have a globally reachable address, simplifying end-to-end connectivity, peer-to-peer applications, self-hosting, and network troubleshooting. For operators who run servers, labs, or BGP-based networks, this architectural clarity is a major advantage.

IPv6 introduces Stateless Address Autoconfiguration (SLAAC), which allows devices to generate their own IPv6 address automatically by combining a prefix advertised by the local router with a self-generated interface identifier. This removes the dependency on DHCP for basic address assignment, though DHCPv6 remains available for networks that require stateful configuration, DNS server discovery, or additional parameters.

The Neighbor Discovery Protocol (NDP) replaces ARP in IPv6. NDP handles address resolution, router discovery, duplicate address detection, and redirect functions using ICMPv6 messages. While NDP is more efficient than the IPv4 ARP mechanism, it is important for operators to understand NDP security considerations, including the use of Secure Neighbor Discovery (SEND) and RA Guard in shared network segments.

A tunnel broker is a service that provides IPv6 connectivity to users or organizations whose Internet service provider does not offer native IPv6. The broker operates IPv6 routers at one or more Points of Presence (PoPs), and establishes a tunnel between the user and the PoP. The user's IPv6 traffic is encapsulated inside IPv4 packets, sent to the broker's PoP, and then routed natively over the IPv6 Internet. Tunnel brokers typically support several encapsulation methods including 6in4 (protocol 41), GRE, OpenVPN, and WireGuard. 6Project provides tunnel broker services with PoPs across Europe, North America, and Asia, supporting OpenVPN, WireGuard, SIT, GRE, and BGP-based connectivity for users who need routed IPv6 prefixes.

IPv6 handles multicast more efficiently than IPv4. The protocol reserves a large portion of its address space for multicast, and multicast group management is integrated into the core protocol rather than added as an extension. This makes IPv6 more suitable for modern applications that rely on one-to-many or many-to-many communication patterns.

IPsec support is built into the IPv6 protocol suite, though its actual use depends on implementation and policy choices. While this does not guarantee automatic encryption of all IPv6 traffic, it means that the protocol stack includes the necessary framework for authentication and encryption without requiring additional layers.

For home users, developers, students, and network operators, adopting IPv6 early provides practical benefits. It enables testing of dual-stack services, access to IPv6-only content and peer-to-peer networks, simpler subnet planning for homelabs, and BGP-capable connectivity for routing experiments. As cloud providers, hosting platforms, content delivery networks, and major ISPs increasingly assume IPv6 availability, having working IPv6 connectivity becomes a prerequisite for full Internet participation.

To check whether your current connection supports IPv6, you can visit a public IPv6 test site such as test-ipv6.com. If the test indicates no IPv6 connectivity, a tunnel broker like 6Project can bridge the gap. The process involves choosing a tunnel method and a nearby PoP, submitting a request with your technical details, and configuring your router or device once the tunnel is provisioned.

The transition from IPv4 to IPv6 has been underway for over a decade and continues to accelerate. Major mobile networks, cloud providers, and content platforms now serve a significant portion of their traffic over IPv6. Understanding IPv6 addressing, autoconfiguration, routing, and tunnel broker options is essential for anyone who manages connected systems or wants to build services that remain reachable as the Internet evolves.

6Project operates AS208753 and provides community-oriented IPv6 tunnel broker services from PoPs in Milan, Paris, Frankfurt, London, Kansas City, Las Vegas, Fremont, New York, Toronto, Sao Paulo, Istanbul, Hong Kong, and Tokyo. The network supports OpenVPN, WireGuard, SIT, GRE, and BGP-based connectivity with /64 and /80 prefix options, making it suitable for a wide range of use cases from simple client access to more advanced routed deployments. BGP is available at all PoPs except Paris.

6Project keeps IPv6 access approachable while encouraging responsible network operations.

1. Explore IPv6 basics, global PoPs, policies, and current service health.
2. Choose a tunnel method and a suitable location for latency and routing quality.
3. Submit accurate technical details so the tunnel can be reviewed and provisioned.

IPv6 connectivity should be practical, observable, and useful for real learning. 6Project network operations

External resources

• User dashboard
• 6Project on PeeringDB
• AS208753 PeeringDB network
• AS208753 on bgp.tools
• RIPEstat AS208753
• Globalping network probes
• Test IPv6 connectivity
• IPv6 RFC 8200