Information About Port Tracking - Cisco MDS 9000 Series Configuration Manual

Configuring Port Tracking

Information About Port Tracking

Generally, hosts can instantly recover from a link failure on a link that is immediately (direct link) connected
to a switch. However, recovering from an indirect link failure between switches in a WAN or MAN fabric
with a keep-alive mechanism is dependent on several factors such as the time out values (TOVs) and on
registered state change notification (RSCN) information.
In Figure 22: Traffic Recovery Using Port Tracking, on page
recovery can be immediate. However, when the ISL 2 fails between the two switches, recovery depends on
TOVs, RSCNs, and other factors.
Figure 22: Traffic Recovery Using Port Tracking
The port tracking feature monitors and detects failures that cause topology changes and brings down the links
connecting the attached devices. When you enable this feature and explicitly configure the linked and tracked
ports, the Cisco NX-OS software monitors the tracked ports and alters the operational state of the linked ports
on detecting a link state change.
The following terms are used in this chapter:
• Tracked ports—A port whose operational state is continuously monitored. The operational state of the
• Linked ports—A port whose operational state is altered based on the operational state of the tracked
tracked port is used to alter the operational state of one or more ports. Fibre Channel, VSAN, PortChannel,
FCIP, or a Gigabit Ethernet port can be tracked. Generally, ports in E and TE port modes can also be Fx
ports.
ports. Only a Fibre Channel port can be linked.
281, when the direct link 1 to the host fails,
Cisco MDS 9000 Series Interfaces Configuration Guide, Release 8.x

Information About Port Tracking

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