Alcatel Carrier Internetworking Solutions Switch/Router 用户手册

Page 21-2

The Mapping Adjacency Protocol (

XMAP

) is used to discover the topology of OmniS/Rs in a 

particular installation. Using this protocol, each switch determines which OmniS/Rs are adja-
cent to it by sending and responding to Hello update packets. For the purposes of 

XMAP

, 

adjacent switches are those that: 

• have a Spanning Tree path between them

• do not have any switch between them on the Spanning Tree path that has 

XMAP

 enabled

♦ Note ♦

XMAP

 replaces the Adjacency Only mode of earlier 

versions of 

VAP

.

In the illustration here, all switches are on the Spanning Tree path. Omni Switch/Router A 
and Omni Switch/Router C have 

XMAP

 enabled. Omni Switch/Router B does not. Omni 

Switch/Router A is adjacent to Omni Switch/Router C and vice versa. If Omni Switch/Router B 
enables 

XMAP

, the adjacency changes. A would be adjacent to B, B would be adjacent to both 

A and C, and C would be adjacent to B.