PLANET XGS3-24040 - Manual (Page 97)

Chapter 10 ULDP Function Configuration
10-5
In the network topology in Graph, port g1/1 and port g1/2 of SWITCH A as well as port g1/3 and port g1/4 of
SWITCH B are all fiber ports. And the connection is cross connection. The physical layer is connected and
works normally, but the data link layer is abnormal. ULDP can discover and disable this kind of error state of
link. The final result is that port g1/1, g1/2 of SWITCH A and port g1/3, g1/4 of SWITCH B are all shut down by
ULDP. Only when the connection is correct, can the ports work normally (won’t be shut down).
Switch A configuration sequence:
SwitchA(config)#uldp enable
SwitchA(config)#interface ethernet 1/1
SwitchA (Config-If-Ethernet1/1)#uldp enable
SwitchA (Config-If-Ethernet1/1)#exit
SwitchA(config)#interface ethernet1/2
SwitchA(Config-If-Ethernet1/2)#uldp enable
Switch B configuration sequence:
SwitchB(config)#uldp enable
SwitchB(config)#interface ethernet1/3
SwitchB(Config-If-Ethernet1/3)#uldp enable
SwitchB(Config-If-Ethernet1/3)#exit
SwitchB(config)#interface ethernet1/4
SwitchB(Config-If-Ethernet1/4)#uldp enable
As a result, port g1/1, g1/2 of SWITCH A are all shut down by ULDP, and there is notification information on
the CRT terminal of PC1.
%Oct 29 11:09:50 2007 A unidirectional link is detected! Port Ethernet1/1 need to be shutted down!
%Oct 29 11:09:50 2007 Unidirectional port Ethernet1/1 shut down!
%Oct 29 11:09:50 2007 A unidirectional link is detected! Port Ethernet1/2 need to be shutted down!
%Oct 29 11:09:50 2007 Unidirectional port Ethernet1/2 shutted down!
Port g1/3, and port g1/4 of SWITCH B are all shut down by ULDP, and there is notification information on the
CRT terminal of PC2.
%Oct 29 11:09:50 2007 A unidirectional link is detected! Port Ethernet1/3 need to be shutted down!
%Oct 29 11:09:50 2007 Unidirectional port Ethernet1/3 shutted down!
%Oct 29 11:09:50 2007 A unidirectional link is detected! Port Ethernet1/4 need to be shutted down!
%Oct 29 11:09:50 2007 Unidirectional port Ethernet1/4 shutted down!
10.4 ULDP Troubleshooting
Configuration Notice:
 In order to ensure that ULDP can discover that the one of fiber ports has not connected or the ports are