+7(495) 797-3311 www.qtech.ruМосква, Новозаводская ул., 18, стр. 160down!%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 shutteddown!%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 notificationinformation on the CRT terminal of PC2.%Oct 29 11:09:50 2007 A unidirectional link is detected! Port Ethernet1/3 need to be shutteddown!%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 shutteddown!%Oct 29 11:09:50 2007 Unidirectional port Ethernet1/4 shutted down!7.4 ULDP TroubleshootingConfiguration Notice:In order to ensure that ULDP can discover that the one of fiber ports has not connected or theports are incorrectly cross connected, the ports have to work in duplex mode and have thesame rate.If the automatic negotiation mechanism of the fiber ports with one port misconnected decidesthe working mode and rate of the ports, ULDP won’t take effect no matter enabled or not. Insuch situation, the port is considered as “Down”.In order to make sure that neighbors can be correctly created and unidirectional links can becorrectly discovered, it is required that both end of the link should enable ULDP, using thesame authentication method and password. At present, no password is needed on both ends.The hello interval of sending hello messages can be changed (it is10 seconds by default andranges from 5 to 100 seconds) so that ULDP can respond faster to connection errors of links indifferent network environments. But this interval should be less than 1/3 of the STPconvergence time. If the interval is too long, a STP loop will be generated before ULDPdiscovers and shuts down the unidirectional connection port. If the interval is too short, thenetwork burden on the port will be increased, which means a reduced bandwidth.ULDP does not handle any LACP event. It treats every link of TRUNK group (like Port-channal,TRUNK ports) as independent, and handles each of them respectively.ULDP does not compact with similar protocols of other vendors, which means users can notuse ULDP on one end and use other similar protocols on the other end.ULDP function is disabled by default. After globally enabling ULDP function, the debug switchcan be enabled simultaneously to check the debug information. There are several DEBUGcommands provided to print debug information, such as information of events, state machine,
