/info/l3/nbrcache
IPv6 Neighbor Cache Information Menu
This menu lets you dump IPv6 Neighbor Cache information.
[IP6 Neighbor Discovery Protocol Menu] find - Show neighbor cache entry by IP address port - Show neighbor cache entries on a single port vlan - Show neighbor cache entries on a single VLAN refpt - Show neighbor cache entries per SP summary - Show IP6 neighbor cache summary dump - Show all IP6 neighbor cache entries |
IPv6 Neighbor Cache Information Menu (/info/l3/nbrcache)
Command Syntax and Usage |
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find <IPv6 address> |
| Displays neighbor cache entry by IP address. |
port <port number> |
| Displays neighbor cache entries on a single port. |
vlan <vlan id> |
| Displays neighbor cache entries on a single VLAN. |
refpt <sp id> |
| Displays neighbor cache entries per SP. |
summary |
| Displays a summary of IPv6 neighbor cache entries. |
dump |
| Displays all IPv6 neighbor cache entries. |
IPv6 uses the Neighbor Discovery (ND) protocol to discover its neighbors’ link layer addresses and reachabilty. ND can also auto-configure addresses and detect duplicate addresses. ND enables routers to advertise their presence and address prefixes, and to inform hosts of a better next hop address to forward packets.
Note: Once the Neighbor Cache table reaches 2000 entries, table entries are replaced by adding the new entry and dropping the 2000th entry off the list. Table entries are kept until the entry is replaced by a new one. During this period, no new entries are used to sort for display.
The information collected from ND is stored in the Neighbor Cache. The Neighbor Cache maintains information about each neighbor such as:

MAC Address

VLAN

Ingress port
Neighbor Cache entries are added under the following situations:

Entries are added when an IPv6 Interface or Virtual IP is operational.

Reception of ND messages from neighbor.

A device sends ND packets to resolve a link layer address to which it is attempting to send packets.
The following table describes the reachability states:
Neighbor Cache Reachability States
State | Description |
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Incomplete | The link layer address of the neighbor has not yet been determined. |
Reachable | The neighbor is known to have been reachable recently. |
Stale | The neighbor is no longer known to be reachable, but until traffic is sent to the neighbor, no attempt should be made to verify its reachability. |
Delay | The neighbor is no longer known to be reachable, and traffic has recently been sent to the neighbor. |
Probe | The neighbor is no longer known to be reachable, and ND messages are sent to the neighbor to verify reachability. |
The following table describes the neighbor types:
Neighbor Cache Neighbor Types
Type | Description |
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Local | Pre-configured addresses on Alteon. |
Dynamic | Neighbor addresses learned from ND. |