IPv6: Click, Clack, Front and Back
So although IPSec is a mandatory part of IPv6, it's not mandatory to use it. It's nice to have seat belts, and having seat belts built in does make it more likely people will use them.
So although IPSec is a mandatory part of IPv6, it's not mandatory to use it. It's nice to have seat belts, and having seat belts built in does make it more likely people will use them.
One of the first problems facing any layer three protocol is address resolution. Given an IP packet, how to deliver that to an Ethernet interface?
The Neighbor Discovery Protocol (NDP) was originally designed to do the equivalent of ARP in IPv4. That is, to resolve layer three addresses into layer two addresses. Later the protocol was extended to handle other functions, like duplicate address discovery, router redirects, router advertisements and neighbor reachability.
“Better the devil you know than the devil you don't”. No matter how bad something is, knowing about it is half the battle won. So when something new comes along, like IPv6, its very newness is an issue.