Login
- Table of Contents
-
- 06-Layer 3 - IP Services Configuration Guide
- 00-Preface
- 01-ARP Configuration
- 02-IP Addressing Configuration
- 03-DHCP Configuration
- 04-DNS Configuration
- 05-NAT Configuration
- 06-IP Forwarding Basics Configuration
- 07-Adjacency Table Configuration
- 08-IP Performance Optimization Configuration
- 09-UDP Helper Configuration
- 10-IPv6 Basics Configuration
- 11-DHCPv6 Configuration
- 12-IPv6 DNS Configuration
- 13-Tunneling Configuration
- 14-GRE Configuration
- Related Documents
-
| Title | Size | Download |
|---|---|---|
| 07-Adjacency Table Configuration | 67.76 KB |
|
|
NOTE: · The adjacency table feature only applies to hardware forwarding, but not software forwarding. · The adjacency table feature does not apply to Ethernet networks that use ARP for storing and managing neighbor information. · You can only view adjacency entries on tunnel interfaces and POS interfaces. For more information about tunnel interfaces, see Layer 3—IP Services Configuration Guide. For more information about POS interfaces, see Interface Configuration Guide. |
Adjacency table overview
Introduction to adjacency table
An adjacency table stores information about active neighbors, including neighbor network layer address (nexthop), outgoing interface, link layer service type, and link layer address (not available for PPP).
The concept of neighbor is relevant to network layer. Node B may be an IP neighbor, but not an IPX neighbor of node A. Also, a neighbor in the active state is in relation to network layer. The adjacency table feature only supports the neighbor concept in relation to IP.
A device can be connected with its neighbors through multiple link layer protocols. PPP and FR have their own neighbors.
The switch can apply the adjacency table to the drivers to implement hardware forwarding. In hardware forwarding, the link layer header of the packet to be forwarded is quickly filled according to the adjacency table, and then the packet is forwarded through the outgoing interface.
Fields
Some fields in the adjacency table are describes as follows:
· Routing interface—Outgoing interface in a route entry.
· Physical interface—An existing physical interface, such as POS interface.
· Service type—Type of service corresponding to the adjacency table, such as PPP.
· Action type—Action to take on the packet that matches the entry, forward or drop.
· Link media type—Related to the link layer protocol used by the outgoing interface. P2P indicates point-to-point, such as the point-to-point protocol (PPP).
· Link head information (IPv6)—Information of the link layer header corresponding to the IPv6 protocol.
Displaying and maintaining adjacency table
|
Task |
Command |
Remarks |
|
Display IPv4 adjacency entries. |
display adjacent-table { all | physical-interface interface-type interface-number | routing-interface interface-type interface-number | slot slotnum } [ count | verbose ] [ | { begin | exclude | include } regular-expression ] |
Available in any view |
|
Display IPv6 adjacency entries. |
display ipv6 adjacent-table { all | physical-interface interface-type interface-number | routing-interface interface-type interface-number | slot slotnum } [ count | verbose ] [ | { begin | exclude | include } regular-expression ] |
Available in any view |
