Information About Unified Ports; About The Unidirectional Link Detection Parameter - Cisco Nexus 5000 Series Configuration Manual

Information About Unified Ports

The interface numbering convention is extended to support use with a Cisco Nexus 2000 Series Fabric Extender
as follows:
switch(config)# interface ethernet [chassis/]slot/port
• Chassis ID is an optional entry to address the ports of a connected Fabric Extender. The chassis ID is
Information About Unified Ports
Beginning in Cisco NX-OS Release 5.0(3)N1(1b), Cisco introduces unified port technology. Cisco Nexus
unified ports allow you to configure a physical port on a Cisco Nexus 5500 Platform switch as a 1/10-Gigabit
Ethernet, Fibre Channel over Ethernet (FCoE), or 1-, 2-, 4-, 8-Gigabit native Fibre Channel port.
Currently, most networks have two types of switches for different types of networks. For example, LAN
switches carry Ethernet traffic up to Catalyst switches and SAN switches carry FC traffic from servers to
MDS switches. With unified port technology, you can deploy a unified platform, unified device, and unified
wire approach. Unified ports allow you to move from an existing segregated platform approach where you
choose LAN and SAN port options to transition to a single, unified fabric that is transparent and consistent
with existing practices and management software. A unified fabric includes the following:
• Unified platform—Uses the same hardware platform and the same software code level and certifies it
• Unified device—Runs LAN and SAN services on the same platform switch. The unified device allows
• Unified wire—Converges LAN and SAN networks on a single converged network adapter (CNA) and
A unified fabric allows you to manage Ethernet and FCoE features independently with existing Cisco tools.
The new Cisco Nexus 5548UP switch and the Cisco Nexus 5596UP switch provides built-in unified port
technology. In addition, a new unified port expansion module and two Layer 3 modules increase the benefits
of a deployed unified fabric. For information on the new Cisco Unified Port switches and modules, see the
Cisco Nexus 5000 Series and Cisco Nexus 2000 Series Release Notes for Cisco NX-OS Release 5.0(3)N1(1b)
and NX-OS Release 5.0(3)N1(1c)

About the Unidirectional Link Detection Parameter

The Cisco-proprietary Unidirectional Link Detection (UDLD) protocol allows ports that are connected through
fiber optics or copper (for example, Category 5 cabling) Ethernet cables to monitor the physical configuration
of the cables and detect when a unidirectional link exists. When the switch detects a unidirectional link, UDLD
shuts down the affected LAN port and alerts the user. Unidirectional links can cause a variety of problems,
including spanning tree topology loops.
UDLD is a Layer 2 protocol that works with the Layer 1 protocols to determine the physical status of a link.
At Layer 1, autonegotiation takes care of physical signaling and fault detection. UDLD performs tasks that
autonegotiation cannot perform, such as detecting the identities of neighbors and shutting down misconnected
LAN ports. When you enable both autonegotiation and UDLD, Layer 1 and Layer 2 detections work together
to prevent physical and logical unidirectional connections and the malfunctioning of other protocols.
Cisco Nexus 5000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.0(3)N1(1)
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configured on a physical Ethernet or EtherChannel interface on the switch to identify the Fabric Extender
discovered via the interface. The chassis ID ranges from 100 to 199.
once for your LAN and SAN environments.
you to connect your Ethernet and Fibre Channel cables to the same device.
connects them to your server.
and the Cisco Nexus 5000 Series Hardware Installation
Configuring Ethernet Interfaces
Guide.