Alcatel Carrier Internetworking Solutions Switch/Router 사용자 설명서

Page 21-8

The 

VLAN

 Advertisement Protocol (

VAP

) is an interswitch protocol that keeps the 

VLAN

 

membership databases stored on switches in sync and enables the auto-discovery of network 
nodes. 

VAP

 is useful when you want all 

VLAN

s to communicate over a backbone, but do not 

want locally connected devices to receive all backbone traffic. 

In order for a switch to participate in 

VAP

 exchanges, 

VAP

 must be enabled through a soft-

ware configuration command. The switch does not need to have attached devices that are a 
part of all groups and 

VLAN

s for which 

VAP

 information is exchanged; however, all groups 

and 

VLAN

s must be defined on each switch.

Each switch in a network maintains an AutoTracker database. This database is built by 
observing traffic that matches user-configured policies. The 

VAP

 protocol reads this database 

on all switches and then advertises entries in the database to all other switches in the 
network. 

VAP

 updates nodes on any new entries in AutoTracker databases every 60 seconds. 

VAP

 also stores information in its own database. Currently this information is used by 

SNMP

-

based network management software. The database contains information on 

VLAN

 member-

ship; it maps each learned 

MAC

 address to a group and to any associated 

VLAN

s. This data-

base can contain information on up to 

40,000 MAC

 addresses. 

VAP packets sent
between switches.

VAP packets sent
between switches.