In the following figure, when the direct link 1 to the host fails, recovery can be immediate. However, when
the ISL 2 fails between the two switches, recovery depends on TOVs, RSCNs, and other factors.
Figure 46: Traffic Recovery Using Port Tracking
Port tracking monitors and detects failures that cause topology changes and brings down the links that connect
the attached devices. When you enable this feature and explicitly configure the linked and tracked ports, the
switch 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
tracked port is used to alter the operational state of one or more ports. Fibre Channel, VSAN, SAN port
channel, or a Gigabit Ethernet port can be tracked. Generally, ports in E and TE port modes can also be
F ports.
•
Linked ports
—
A port whose operational state is altered based on the operational state of the tracked
ports. Only physical Fibre Channel ports can be linked ports.
Port tracking has the following features:
•
The application brings the linked port down when the tracked port goes down. When the tracked port
recovers from the failure and comes back up again, the linked port is also brought up automatically
(unless otherwise configured).
•
You can forcefully continue to keep the linked port down, even though the tracked port comes back up.
In this case, you must explicitly bring up the linked port when required.
Related Topics
About RSCN Information, on page 191
Fibre Channel Timeout Values, on page 213
Default Settings for Port Tracking
The following table lists the default settings for port tracking parameters.
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Configuring Port Tracking
Default Settings for Port Tracking
