Neighbor Discovery Protocol (NDP):
* NDP is a key protocol in the IPv6 protocol suite, replacing ARP (Address Resolution Protocol) in IPv4.
* It operates using ICMPv6 (Internet Control Message Protocol for IPv6) and is critical for managing interactions between IPv6 nodes on the same link.
HCIP-Datacom-Core Technology Training Material (NDP Functions and Features).
NDP Features and Functions:
A). Address resolution:NDP resolves IPv6 addresses into MAC addresses, similar to ARP in IPv4. It uses Neighbor Solicitation (NS) and Neighbor Advertisement (NA) messages for this purpose.Reference: HCIP- Datacom-Core Technology Training Material (Address Resolution in IPv6).
B). Neighbor state tracing:NDP tracks the state of neighbors to determine their reachability. It maintains a neighbor cache and uses NS/NA messages to verify whether neighbors are reachable.Reference: HCIP- Datacom-Core Technology Training Material (Neighbor Reachability in IPv6).
C). Duplicate address detection (DAD):NDP ensures that IPv6 addresses are unique within a network.
Before assigning an address to an interface, DAD is used to verify that no other node is using the same address. This is done via NS messages.Reference: HCIP-Datacom-Core Technology Training Material (IPv6 Address Assignment and DAD).
D). Redirection:NDP provides redirection functionality to inform hosts of a better first-hop router for reaching a particular destination. It uses ICMPv6 Redirect messages for this purpose.Reference: HCIP-Datacom- Core Technology Training Material (NDP Redirect Functionality).
Conclusion:NDP supports all the mentioned functions and features: Address resolution, Neighbor state tracing, Duplicate address detection, and Redirection, making it indispensable for IPv6 networks.