About the adjacency table

The adjacency table stores information about directly connected neighbors for IP forwarding. The neighbor information in this chapter refers to non-Ethernet neighbor information.

This table is not user configurable. The neighbor information is generated, updated, and deleted by link layer protocols through negotiation (such as PPP dynamic negotiation) or through manual configuration (such as ATM static configuration). An adjacency entry includes the following information:

• Neighbor network layer address (next hop).

• Output interface.

• Link layer protocol type.

• Link layer address. This field displays PVC for ATM, and it is not available for PPP.

When forwarding an IP packet, the device performs the following tasks:

• Searches the FIB to find the output interface and next hop.

• Uses the output interface and next hop address to search the adjacency table for link layer forwarding information.

	NOTE: Ethernet and non-Ethernet neighbor information are stored and managed together.