ICMPv6 messages used by IPv6 neighbor discovery
The IPv6 neighbor discovery (ND) process uses ICMP messages for address resolution, neighbor reachability verification, and neighboring device tracking.
Table 9 describes the ICMPv6 messages used by the IPv6 ND protocol.
Table 9: ICMPv6 messages used by ND
ICMPv6 message | Type | Function |
|---|---|---|
Neighbor Solicitation (NS) | 135 | Acquires the link-layer address of a neighbor on the local link. |
Verifies the reachability of a neighbor. | ||
Detects duplicate addresses. | ||
Neighbor Advertisement (NA) | 136 | Responds to an NS message. |
Notifies the neighboring nodes of link layer changes. | ||
Router Solicitation (RS) | 133 | Requests an address prefix and other configuration information for autoconfiguration after startup. |
Router Advertisement (RA) | 134 | Responds to an RS message. |
Advertises information, such as the Prefix Information options and flag bits. | ||
Redirect | 137 | Informs the source host of a better next hop on the path to a particular destination when certain conditions are met. |