IPv6 and Mobility FAQ

Questions:

Answers:

  A: IPv6 is the new version of the Internet Protocol, used to deliver your data over the Internet. For detailed information about IPv6 you should read the Wikipedia IPv6 page.

  A: The benefit of IPv6 is its huge address space. While IPv4 has 32-bit address space that can identify only 4.3 billion (4294967296) nodes at maximum, IPv6 can identify 340282366920938463463374607431768211456 nodes with its 128-bit address space. This means IPv6 addresses can be assigned to almost anything connected to the Internet. In the future, more and more devices will connect to the Internet and they will communicate with each other directly. In such situation, the mechanism to identify each device with global accessible identifiers becomes more important. IPv6 is one of the realistic solution for the future networking environment.

  A: IP addresses are allocated hierarchically based on the network topology. Every edge network will have different network prefixes and each node connected to the edge network will have an IP address assigned from the address space related to the network prefix of the edge network. The address assigned in one edge network is not valid and usable in other edge networks. Because the communication channel between two IP nodes is identified with their IP addresses, changing the IP address means the termination of the communication. If one node moves from one edge network to other network, the ongoing communication will be terminated because the address assigned to the node will change to a new address based on the network prefix of the new edge network.

However, recent progress of communication technology and device technology enables many small communication devices that can have multiple network interfaces. Such nodes are potentially mobile nodes and will change its point of attachment to the Internet frequently. IP mobility is proposed to support these nodes running in a mobile environment. With IP mobility technology, moving nodes can use fixed IP addresses regardless of its point of attachment to the Internet and thus can continue its communication while moving around the Internet.

  A: Some operating systems support IPv6 mobility technology.

• GNU/Linux with USAGI/MIPL mobility stack
• NetBSD with KAME/SHISA mobility stack
• FreeBSD with KAME/SHISA mobility stack
• HP-UX 11iv2 + TOUR3.0
• HP Tru64 UNIX 5.1Bp1 + Mobile IPv6 V4.0
• Treck Inc., Treck Embedded Mobile IPv6
• 6WIND, 6WINDGate
• Cisco, IOS 12.4 and 12.2S

Some more information may be found at Mobile IP implementations page.