Alcatel Carrier Internetworking Solutions Switch/Router 사용자 설명서

Page 21-3

XMAP

 switch ports are either in the discovery transmission state, common transmission state, 

or passive reception state. Ports transition to these states depending on whether or not they 
receive Hello responses from adjacent switches.

♦ Note ♦

All Hello packet transmissions are sent to a well-known 

MAC

 address (0020DA000003).

The transmission states are illustrated here. 

When 

XMAP

 is active, at startup all active switch ports are in the discovery transmission state. 

In this state ports send out Hello packets and wait for Hello responses. Ports send out Hello 
packets at a configurable interval called the discovery transmission time. The discovery trans-
mission time is configurable; 30 seconds is the default. The ports send out Hello packets up 
to three timeouts of this interval trying to discover adjacent switches.

Any switch ports that receive Hello packets before three discovery transmission times expire 
send a Hello reply and transition to the common transmission state. Any switch ports that do 
not receive a Hello response before three discovery transmission times have expired are 
placed in the passive reception state.

No

Hello packets 

received before

3 discovery transmis-

sion timeouts

Yes

No

Yes

No Hello packets 

received after

3 discovery transmis-

sion timeouts.