Specifications

Preparing for Installation
Catalyst 1900 Series Installation and Configuration Guide
2-6
Powering Up and Using POST to Test the Switch
Before installing and connecting the switch to other network devices, you might want to
power up the switch and verify that it is operational. To power up the switch, connect one
end of the AC power cord to the AC power connector on the switch and the other end of the
power cord to a power outlet. If your switch connects to the RPS, see the “Power
Connectors” section on page 1-12 and the Cisco RPS documentation.
As the switch powers up, it begins the power-on self-test (POST), the 13 individual tests
listed in Table 5-2. The port LEDs show which test the switch is executing. At power up,
all port LEDs are green. As each test executes, a port LED turns off. For example, if the
LED for port 4x is off, the console port test (test 4) is being executed. On a switch with 12
10BaseT ports, the port LED for port Ax (or port A) turns off first, followed by ports 12x,
11x, 10x, and so on. On a switch with 24 10BaseT ports, the port LED for port 16x turns
off first, followed by ports 12x, 11x, 10x, and so on. The LEDs for ports 15x, 14x, 13x are
not used during POST. The LED for port Bx is not used during POST.
When POST ends, the following conditions can exist:
• All POST tests passed—If the SYSTEM LED is green and all of the port LEDs are off,
no problems were detected. The switch is fully operational.
Note If there are devices connected to the switch ports when POST ends,
Spanning-Tree Protocol (if enabled) immediately turns those port LEDs amber. The
forwarding state, even if the Port Fast mode is enabled, is delayed to allow the
Spanning-Tree Protocol to discover the network topology and to ensure no temporary
loops are formed. Spanning-tree discovery takes approximately 30 seconds, and no
packets are forwarded during this time. After the initial discovery, ports with Port Fast
mode enabled go directly from the blocking state to the forwarding state.
• Nonfatal failure(s) detected—If the SYSTEM LED is amber and the switch is
functional, POST detected one or more nonfatal failures. The switch is still operational
and can forward packets, but it might not operate optimally. The Management Console
Logon Screen displays the POST failure message that identifies the nonfatal failure(s)
detected.