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- Table of Contents
-
- 05-Layer 3 - IP Services Configuration Guide
- 00-Preface
- 01-ARP configuration
- 02-IP addressing configuration
- 03-DHCP configuration
- 04-DNS configuration
- 05-IP forwarding basics configuration
- 06-Fast forwarding configuration
- 07-Adjacency table configuration
- 08-IRDP configuration
- 09-IP performance optimization configuration
- 10-UDP Helper configuration
- 11-IPv6 basics configuration
- 12-DHCPv6 configuration
- 13-IPv6 fast forwarding configuration
- 14-Tunneling configuration
- 15-GRE configuration
- Related Documents
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| Title | Size | Download |
|---|---|---|
| 07-Adjacency table configuration | 40.03 KB |
Displaying the adjacency table
The adjacency table stores information about directly connected neighbors for IP forwarding. The neighbor information in the adjacency table 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. An adjacency entry contains the neighbor network layer address (next hop), output interface, link layer protocol type, and link layer address.
When forwarding an IP packet, the device does the following:
· 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 that is required for forwarding the packet.
The following table shows the items contained in an adjacency table output:
|
Item |
Description |
|
IP address |
IP address of the next hop in FIB table for packet forwarding. This address is used for adjacency table lookup. |
|
Routing interface |
Output interface in the matching route entry. This interface is used for adjacency table lookup, and it can be logical or physical. |
|
Physical interface |
Output physical interface that sends matching packets. If the routing interface is physical, the routing interface and physical interface are the same. If the routing interface is logical, the routing interface and physical interface are different. |
|
Logical interface |
Logical interface for sending packets, such as a Virtual-Template interface for MP. |
|
Service type |
Link layer protocol type, such as Tunnel. |
|
Action type |
Action to be taken on the matching packet: Forwarding or Drop. |
|
Link media type |
Related to the link layer protocol used by the routing interface. P2P indicates a point-to-point link, and NBMA indicates a non-broadcast multi-access link. |
|
Link head information(IP) |
Link layer header for IP forwarding. |
|
Link head information(IPv6) |
Link layer header for IPv6 forwarding. |
|
Link head information(MPLS) |
Link layer header for MPLS forwarding. |
To display adjacency table entries, use one of the following commands in any view:
|
Task |
Command |
|
Display IPv4 adjacency table information. |
display adjacent-table { all | physical-interface interface-type interface-number | routing-interface interface-type interface-number | slot slot-number } [ count | verbose ] |
|
Display IPv6 adjacency table information. |
display ipv6 adjacent-table { all | physical-interface interface-type interface-number | routing-interface interface-type interface-number | slot slot-number } [ count | verbose ] |
