Alcatel-Lucent OmniSwitch 9900 Series Network Configuration Manual page 65

UniDirectional Link Detection (UDLD) is a protocol for detecting and disabling unidirectional Ethernet
fiber or copper links caused by mis-wiring of fiber strands, interface malfunctions, media converter faults,
and so on. The UDLD protocol operates at Layer 2 in conjunction with the IEEE 802.3 - Layer 1 fault
detection mechanisms.
UDLD is a lightweight protocol that can be used to detect and disable one-way connections before they
create dangerous situations such as Spanning Tree loops or other protocol malfunctions. The protocol is
mainly used to advertise the identities of all the UDLD-capable devices attached to the same LAN
segment and to collect the information received on the ports of each device to determine whether or not
the Layer 2 communication is functioning properly. All connected devices must support UDLD for the
protocol to successfully identify and disable unidirectional links. When UDLD detects a unidirectional
link, the protocol administratively shuts down the affected port and generates a trap to alert the user.
In This Chapter
This chapter describes how to configure UDLD parameters through the Command Line Interface (CLI).
CLI commands are used in the configuration examples; for more details about the syntax of commands,
see the OmniSwitch AOS Release 8 CLI Reference Guide.
Configuration procedures described in this chapter include the following:
•
"Configuring UDLD" on page
•
"Configuring the Operational Mode" on page
•
"Configuring the Probe-Timer" on page
•
"Configuring the Echo-Wait-Timer" on page
•
"Clearing UDLD Statistics" on page
•
"Verifying the UDLD Configuration" on page
•
"Verifying the UDLD Configuration" on page
OmniSwitch AOS Release 8 Network Configuration Guide
2 Configuring UDLD
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