User's Manual

Configuration Guide of XGS-5240-Series
114
SwitchA(config)#interface ethernet 1/0/2
SwitchA(Config-If-Ethernet1/0/2)#uldp enable
Switch B configuration sequence:
SwitchB(config)#uldp enable
SwitchB(config)#interface ethernet1/0/3
SwitchB(Config-If-Ethernet1/0/3)#uldp enable
SwitchB(Config-If-Ethernet1/0/3)#exit
SwitchB(config)#interface ethernet 1/0/4
SwitchB(Config-If-Ethernet1/0/4)#uldp enable
As a result, port g1/0/1, g1/0/2 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 Ethernet1/0/1 need to be
shutted down!
%Oct 29 11:09:50 2007 Unidirectional port Ethernet1/0/1 shut down!
%Oct 29 11:09:50 2007 A unidirectional link is detected! Port Ethernet1/0/2 need to be
shutted down!
%Oct 29 11:09:50 2007 Unidirectional port Ethernet1/0/2 shutted down!
Port g1/0/3, and port g1/0/4 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 Ethernet1/0/3 need to be
shutted down!
%Oct 29 11:09:50 2007 Unidirectional port Ethernet1/0/3 shutted down!
%Oct 29 11:09:50 2007 A unidirectional link is detected! Port Ethernet1/0/4 need to be
shutted down!
%Oct 29 11:09:50 2007 Unidirectional port Ethernet1/0/4 shutted down!
12.4 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 incorrectly cross connected, the ports have to work in duplex mode and
have the same rate.
 If the automatic negotiation mechanism of the fiber ports with one port misconnected
decides the working mode and rate of the ports, ULDP won’t take effect no matter
enabled or not. In such situation, the port is considered as “Down”.
 In order to make sure that neighbors can be correctly created and unidirectional links can
be correctly discovered, it is required that both end of the link should enable ULDP, using
the same authentication method and password. At present, no password is needed on