Troubleshooting Aids

Certain troubleshooting aids of the Cisco NCS 520 enable you to perform these tasks that assist the troubleshooting process:

Verify Pinout

Pinouts provide input signal (to the device) and output signal (from the device) information. Time-of-Day Port (TOD) port, Alarm (ALARM) port, and Management Ethernet (MGMT) port pinout information is provided in the following sections.

Time-of-Day Port Pinouts

The following table summarizes the ToD/1-PPS port pinouts.

Table 1. RJ-45 1PPS/ToD Port Pinouts

Pin

Signal Name

Direction

Description

1

RESERVED

Output

Do Not Connect

2

RESERVED

Input

Do Not Connect

3

1PPS_N

Output or Input

1PPS RS422 signal

4

GND

—

—

5

GND

—

—

6

1PPS_P

Output or Input

1PPS RS422 signal

7

TOD_N

Output or Input

Time-of-Day character

8

TOD_P

Output or Input

Time-of-Day character

Alarm Port Pinouts

The following table summarizes the external alarm input pinouts.

Table 2. External Alarm Input Pinouts

Pin

Signal Name

Description

1

ALARM0_IN

Alarm input 0

2

ALARM1_IN

Alarm input 1

3

—

No connect

4

ALARM2_IN

Alarm input 2

5

ALARM3_IN

Alarm input 3

6

—

No connect

7

—

No connect

8

COMMON

Alarm common

Management Ethernet Port Pinouts

The following table summarizes the Management Ethernet port pinouts.

Table 3. Fan Alarm Port Pinout

Pin

Signal Name

1

TRP0+

2

TRP0-

3

TRP1+

4

TRP2+

5

TRP2-

6

TRP1-

7

TRP3+

8

TRP3-

Check Optical Fiber Specifications

Optical fiber transmission defines two types of fiber specification:

  • Single mode with three transmission types: short reach, intermediate reach, and long reach.

  • Multimode with only short reach.

Check Alarm Conditions

The following table summarizes the meaning of alarm conditions on the device.

Table 4. Alarm Conditions Summary

Alarm Type

Alarm Meaning

Critical

Port in down state.

Environmental sensor threshold exceeded critical level (voltage, temperature).

Major

Environmental sensor threshold exceeded major level (voltage, temperature).

Info

Port is administratively shut down.

Check LED Indicators

This section describes the different types of front panel LEDs and their behavior.

Power LED

The PWR LED provides power on the board and the overall health status of the device. During the power-up state, the LED provides booting status and report errors.


Note
The digital code signing functionality validates the integrity and authenticity of the ROMMON image before booting it.
Table 5. Power LED Indication

LED State

Indication

Green

Board that is powered up, IOS Booted and running

Blinking Green

Bootloader is up

Red

Failure to boot or CPU is in reset

Off

No power

CPU Management Port LEDs

A bicolor LED indicates the status of the management port. The following table gives definition of the MGMT LED indication.

Table 6. CPU Management Port LED Indication

LED

LED State

Indication

MGMT

Green

Link up in 1000 Mbps

Blinking Green

Activity in 1000 Mbps

Amber

Link up in 10/100 Mbps

Blinking Amber

Activity in 10/100 Mbps

SFP+ LEDs

Each port in sets of GE SFP+ ports has an LED indicator.

Table 7. SFP+ Port LED Indication

LED

LED State

Indication

GE / GE SFP

Green

Link up in 10G/1G

Blinking Green

Activity in 10G/1G

Yellow

Fault/Error/Link down

Off

Admin down

Copper GE Ports

The copper GE ports have two status LEDs each. The copper PHY drives these LEDs.

Table 8. Copper GE Port LED Indication

LED State

Indication (LED on the left)

Indication (LED on the right)

Green

Link up in 1G mode.

Link up in full-duplex mode.

Blinking Green

Activity in 1G mode

-

Yellow

Fault or Error

-

Off

Link administratively down

Link up in half-duplex.

Alarm LED

The Alarm port has 3 corresponding LEDs. These LEDs are based on the severity of the alarm condition: CRIT (critical), MAJ (major), and MIN (minor).

Table 9. Alarm LEDs

LED State

CRIT

MAJ

MIN

Off

No alarm

Red

PSU redundancy failure (for redundant systems)

One or more thermal sensors have crossed Critical alarm threshold

-

System in holdover or free-run mode (applicable only on premium devices)

More than one fan failure

Single fan failure

-

Optics temperature crossing thresholds