The following table compares the ICMP message types.
|
IPv4 Function |
IPv6 Function |
Description |
|---|---|---|
|
ARP request message |
Neighbor solicitation message |
A node sends this message to determine the link-layer address of a neighbor or to verify that a neighbor is still reachable through a cached link-layer address. You can also use neighbor solicitations for duplicate address detection. |
|
ARP reply message |
Neighbor advertisement |
A node sends this message either in response to a received neighbor solicitation message or to communicate a link-layer address change. |
|
ARP cache |
Neighbor cache |
The neighbor cache contains information about neighbor types on the network. |
|
Gratuitous ARP |
Duplicate address detection New VRRP master interface announcement |
A host or node sends a request with its own IP address to determine if another router or host uses the address. If the sender receives a reply, then there is a device with a duplicate address. Both hosts and routers use this function. Gratuitous ARP can also be used to announce the new VRRP master interface so that all switches can adjust their MAC tables. |
|
Router solicitation message (optional) |
Router solicitation message (required) |
The host sends this message after it detects a change in a network interface operational state. The message includes a request for routers to generate router advertisement immediately rather than at the scheduled time. |
|
Router advertisement message (optional) |
Router advertisement message (required) |
Routers send this message to advertise their presence with various links and Internet parameters either periodically or in response to a router solicitation message. Router advertisements contain prefixes that you use for on-link determination or address configuration, and a suggested hop limit value. |
|
Redirect message |
Redirect message |
Routers send this message to inform hosts of a better first hop for a destination. |