Understanding Status LEDs
When you power up the system, it runs a series of tests for each module installed in the system. Refer to the tables in this section to understand normal and abnormal LED activity. For troubleshooting information, see Table 8-4.
The system's modules have two sets of status LEDs. The top set indicates generic router and module status. The bottom set indicates module-specific status, such as port status (line modules) or fan status (SRP module).
The number against the port status LED on a line module corresponds to the number of the port on the I/O module. Some line modules have more port status LEDs than the number of ports on the I/O module. In these cases, only the LEDs for the corresponding ports on the I/O modules are active.
For example, an OCx/STMx line module can pair with either an OC3-4 or an OC12/STM4 I/O module. Consequently, the line module has four port status LEDs for OC3/STM1 operation. However, only the top two sets of port status LEDs are active during OC12/STM4 operation.
Table 8-2 shows the functions of the module and port status LEDs.
Table 8-2 LED identification and activity descriptions
See Redundancy Status later in this chapter. If the port is configured as DTE, the LED lights when both the DCE and the clock source are available. If the port is configured as DTE, the LED goes out when either the DCE or the clock source becomes unavailable. If the port is configured as DTE, the LED lights when either the DCE or the clock source becomes unavailable. If the port is configured as DTE, the LE goes out when both the DCE and the clock source are available.
The following figures show a representative module for each of the three variations:
Note: The primary SRP illuminates the REDUNDANT LED only when the SRP detects that there is a secondary or standby SRP module online. The standby SRP monitors an activity signal from the primary SRP module to determine its state; it does not shadow the operations of the primary SRP. If the standby SRP detects that the primary SRP is not active, it reboots the system and takes control.
LED Activity During Booting
When the system boots, it runs diagnostic tests, and the module status LEDs display various configurations. Observe the scenario presented in Table 8-3 to verify that the system has booted properly.
Note: When you reboot the system after installing a new version of the software, the line modules will appear to boot twice.
Table 8-3 Normal activity of functional status LEDS during booting
If the system detects an error during booting, the FAIL LED turns on. Some failure conditions may cause the board not to boot. In this case, the LEDs may all be off. The system should then reset the board.
If the operational software detects an error, the FAIL LED turns on. Some errors may cause a board reset. Crash information can be displayed from the console and is printed to the screen on the next reboot.
Abnormal LED Activity
See Table 8-4 to diagnose and correct problems.
Table 8-4 Troubleshooting abnormal LED activity on modules
2 Review section on proper slot group configuration in Chapter 3, Installing ERX Modules.
You can determine the redundancy state of line modules by examining the online and redundant status LEDs. See Table 8-5.
Note: The REDUNDANT LED on the cOCx/STMx, FE-8, GE/FE, HSSI, and OCx/STMx modules is nonfunctional.
Table 8-5 Redundancy status of a line module