Cisco Nexus 5000 Series Switch Fabric Manager Software Configuration Guide, NX-OS 4.0 (OL-16598-01, June 2008)

CHAPTER
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27-1
Nexus 5000 Series Switch Fabric Manager Software Configuration Guide
OL-16598-01
27
Configuring Port Tracking
Nexus 5000 Series switches offer the port tracking feature on physical Fibre Channel interfaces (but not
on virtual Fibre Channel interfaces). This feature uses information about the operational state of the link
to initiate a failure in the link that connects the edge device. This process of converting the indirect
failure to a direct failure triggers a faster recovery process towards redundant links. When enabled, the
port tracking feature brings down the configured links based on the failed link and forces the traffic to
be redirected to another redundant link.
This chapter includes the following sections:
• Information About Port Tracking, page 27-1
• Configuring Port Tracking, page 27-2
• Default Port Tracking Settings, page 27-7
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 keepalive mechanism is dependent on several factors such as the timeout values
(TOVs) and on registered state change notification (RSCN) information (see the “Fibre Channel Timeout
Values” section on page 22-1 and “About RSCN Information” section on page 19-5).
In Figure 27-1, 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.