Port Beaconing; Bit Error Rate Thresholds; Disabling The Bit Error Rate Threshold - Cisco MDS 9000 Series Configuration Manual

Configuring Interfaces
The switchport encap eisl command is disabled by default. If you enable encapsulation, all outgoing frames
are encapsulated, and you will see a new line (Encapsulation is eisl) in the show interface SD_port_interface
command output. For information about encapsulation, see the
Management Configuration

Port Beaconing

The Port Beaconing feature can be used to identify individual switch and directly attached peer ports in a data
center environment. This feature may be used by a switch administrator to help a data center operations
personnel to identify ports that need to be serviced by replacing cables or small form-factor pluggable
transceivers (SFPs).
The switch administrator can specify a status, duration, and blink rate for switch port beacon LEDs. Port
Beacon LEDs of any directly attached peer port may also be controlled if the peer supports the Link Cable
Beaconing (LCB) Fibre Channel protocol. Port beacon LEDs on either end or both ends of a link may be
controlled using a single command.

Bit Error Rate Thresholds

The bit error rate (BER) threshold is used by a switch to detect an increased error rate before performance
degradation seriously affects traffic.
Bit errors occur because of the following reasons:
• Faulty or bad cable
• Faulty or bad Gigabit Interface Converter (GBIC) or Small Form-Factor Pluggable (SFP)
• GBIC or SFP is specified to operate at 1 Gbps, but is used at 2 Gbps
• GBIC or SFP is specified to operate at 2 Gbps, but is used at 4 Gbps
• Short-haul cable is used for long haul or long-haul cable is used for short haul
• Momentary synchronization loss
• Loose cable connection at one end or both ends
• Improper GBIC or SFP connection at one end or both ends
A BER threshold is detected when 15 error bursts occur in an interval of minimum 45 seconds and a maximum
of 5-minute period with a sampling interval of 3 seconds. By default, the switch disables the interface when
the threshold is reached. Use the shutdown and no shutdown command sequence to re-enable the interface.
You can configure the switch to not disable an interface when the threshold is crossed. By default, the threshold
disables the interface.

Disabling the Bit Error Rate Threshold

By default, the threshold disables the interface. However, you can configure the switch to not disable an
interface when the threshold is crossed.
To disable the BER threshold for an interface, perform these steps:
Guide.
Cisco MDS 9000 Series Interfaces Configuration Guide, Release 8.x
Port Beaconing
Cisco MDS 9000 Series NX-OS System
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