User's Manual

Table Of Contents
Users Manual of GS-5220-8P2T2S Managed Switch
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4.3.12 UDLD
Unidirectional Link Detection (UDLD) is a data link layer protocol from Cisco Systems to monitor the physical configuration of
the cables and detect unidirectional links. UDLD complements the Spanning Tree Protocol which is used to eliminate switching
loops..
4.3.12.1 UDLD Port Configuration
This page allows the user to inspect the current UDLD configurations, and possibly change them as well. as screen
in Figure 4-3-12-1 appears.
Figure 4-3-12-1: UDLD Configuration Page Screenshot
The page includes the following fields:
General Settings
Object Description
Port
Port number of the switch.
UDLD Mode
Configures the UDLD mode on a port. Valid values
are Disable, Normal and Aggressive. Default mode is Disable.
Disable: In disabled mode, UDLD functionality doesn't exists on port..
Normal: In normal mode, if the link state of the port was determined to be
unidirectional, it will not affect the port state.
Aggressive: In aggressive mode, unidirectional detected ports will get
shutdown. To bring back the ports up, need to disable UDLDon that port
Message Interval
Configures the period of time between UDLD probe messages on ports that are
in the advertisement phase and are determined to be bidirectional. The range is
from 7 to 90 seconds(Default value is 7 seconds)(Currently default time interval
is supported, due to lack of detailed information in RFC 5171).