Chapter 3. IPv6 in Depth

“I think there is a world market for maybe five computers.”

—Thomas Watson, CEO of IBM, 1943

This chapter examines in detail Internet Control Message Protocol (ICMP) for IPv6 and path MTU discovery (PMTUD) for IPv6. It also examines in depth the mechanisms in Neighbor Discovery Protocol (NDP) such as the replacement of the Address Resolution Protocol (ARP) in IPv4, stateless autoconfiguration, prefix advertisement, duplicate address detection (DAD), and prefix renumbering. Then you will be able to describe the use of Domain Name System (DNS), Dynamic Host Configuration Protocol (DHCP), IPSec, and Mobile IP with IPv6.

After Chapter 2, “IPv6 Addressing,” which covered enabling IPv6 on the Cisco router and having configured IPv6 addresses on network interfaces, this chapter focuses on the following:

• Managing neighbor entries in the router's neighbor discovery table

• Tuning neighbor discovery messages

• Enabling and tuning prefix advertisement on the interface

• Disabling router advertisements on the router when needed

• Renumbering the prefix advertised on the network interface

• Creating the hosts table (DNS) in the router for IPv6 addresses

• Defining standard and extended IPv6 access control lists (ACLs) with reflexive ACL

• Enabling standard and extended IPv6 ACLs on the network interface

• Using tools such ping, Telnet, traceroute, SSH (Secure Shell), and Trivial File Transfer Protocol (TFTP) with IPv6 on the router for diagnostic and debugging purposes

Finally, with the configuration exercise, you will practice commands learned in this chapter by configuring, analyzing, showing, testing, and debugging IPv6 on the Cisco IOS Software technology.