ULDP Function Configuration
88
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!
8.4
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 a
nd 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 both ends.
The hello interval of sending hello messages can be changed (it is10 seconds by
default and ranges from 5 to 100 seconds) so that ULDP can respond faster to
connection errors of links in different network environments. But this interval should
be less than 1/3 of the STP convergence time. If the interval is too long, a STP loop
will be generated before ULDP discovers and shuts down the unidirectional
connection port. If the interval is too short, the network 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-channel, TRUNK ports) as independent, and handles each of them respectively.