IPv6 Neighbor Discovery

Today we have a focus on the "Neighor Discovery" in IPv6.

Here you can view another Youtube-Video:

https://www.youtube.com/watch?v=6rXn7dcj4xA

The Neighbor Discovery Protocol (NDP) is an alternative of the the ARP (Address Resolution Protocol).
It's a Protocol in IPv6. It's responsible for the exchange of link-local messages.
It's also being used to determine IPv6-addresses into Link-Layer-Addresses (MAC).



A protocol, which is used for this is "ICMP" (Internet Control Message Protocol).
The process uses multicast addresses to determine the link-layer-address of a neighbor on the same network(local link), verify the reachability of a neighbor and track neighboring devices.

Assignments of NDP:

• Router- and Prefix Discovery
• Parameter Discovery (MTU, hop limit, ..)
• Stateless Address Configuration (SLAAC)
• Address Resolution (with Neighbor Discovery)
• Neighbor Unreachability Detection
• Duplicate Address Detection
• Redirect

Common Questions:

• What's the "host autoconfiguration"?

A IPv6-Host can create automatically a link-local & a global address.

• What is a "tentative address" and what is it used for?

A IPv6-address can have many different states. One of them is the state "tentative" (dt.: vorläufig).
In this state, the address isn't definitely assigned to the interface.
The interface is in a state, where the IP-address is going to be tested.
A point cannot communicate over a tentative address in the network.

• Which kind of IPv6-address is "FF02::1"?

The link-local address

• Which steps are necessary before two hosts can exchange messages?