Builtin Features of IPv6

In our last section we learnt about the limitations of IPv4. Now we will discuss built in feature of IPv6.

Very large address space

IPv6's large address space deals with global growth, where route prefixes can be easily aggregated in routing updates.

Security

IP security (IPSec) is built into IPv6, whereas it is an awkward add-on in IPv4. With IPv6, two devices can dynamically negotiate security parameters and build a secure tunnel between them with no user intervention.

Mobility

With the growth of mobile devices, such as PDAs and smart phones, devices can roam between wireless networks without breaking their connections. Streamlined encapsulation The IPv6 encapsulation is simpler than IPv4, providing faster forwarding rates by routers and better routing efficiency.

• No checksums are included, reducing processing on endpoints.
• No broadcasts are used, reducing utilization of devices within the same subnet.

QoS

Information is built into the IPv6 header, where a flow label identifies the traffic; this alleviates intermediate network devices from having to examine contents inside the packet, the TCP/UDP headers, and payload information to classify the traffic for QoS correctly.

Transition capabilities

Various solutions exist to allow IPv4 and IPv6 to successfully coexist when migrating between the two. One method, dual stack, allows you to run both protocols simultaneously on an interface of a device. A second method, tunneling, allows you to tunnel IPv6 over IPv4 and vice versa to transmit an IP version of one type across a network using another type. Cisco supports a third method, referred to as Network Address Translation-Protocol Translation (NAT-PT), to translate between IPv4 and IPv6 (sometimes the term Proxy is used instead of Protocol).

Stateless and Stateful Address Configuration

To simplify host configuration, IPv6 supports both stateful address configuration (such as address configuration in the presence of a DHCP for IPv6, or DHCPv6, server) and stateless address configuration (such as address configuration in the absence of a DHCPv6 server).

New Protocol for Neighboring Node Interaction

The Neighbor Discovery protocol for IPv6 is a series of Internet Control Message Protocol for IPv6 (ICMPv6) messages that manages the interaction of neighboring nodes (nodes on the same link). Neighbor Discovery replaces and extends the Address Resolution Protocol (ARP) (broadcast-based), ICMPv4 Router Discovery, and ICMPv4 Redirect messages with efficient multicast and unicast Neighbor Discovery messages.

Extensibility

IPv6 can easily be extended for new features by adding extension headers after the IPv6 header.