Alcatel Carrier Internetworking Solutions Omni Switch/Router - Manual (Page 648)

XMAP
Page 21-2
XMAP
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.
XMAP Adjacency
OSR A OSR B OSR C
S PANNING T REE P ATH