Chapter 1      Introduction
Hardware Features
1-8
User Guide for the Catalyst Express 520 Switches
OL-12761-02
8ADMIN LEDThe ADMIN LED shows the management mode in which the switch is operating. 
Off (dark) Switch is configured with an IP address.
Blinking green Switch is in the initial setup mode, or the switch is in direct 
managed mode. For information about this mode, see the 
“Device Manager Is Not Accessible Through the Network” 
section on page 7-4.
9 ADMIN button The ADMIN button is used to manage the switch through a direct connection to 
your PC or laptop and is used to start the recovery on the switch.
10 Uplink ports Depending on the Catalyst Express 520 model, the uplink ports can be 
dual-purpose ports or 10/100/1000 ports. For information about 10/100/1000 
ports, see Downlink ports.
The dual-purpose port can be used as either a 10/100/1000 port or as an SFP 
module port. However, both cannot be active at the same time. If both ports are 
connected, the SFP module port has priority. You cannot change this priority 
setting.
The SFP module slot supports Gigabit Ethernet SFP modules to establish 
fiber-optic and 1000BASE-T uplink connections. It supports the modules listed 
in the “Supported Hardware” section on page 1-14.
11 Downlink 
ports
Depending on the Catalyst Express 520 model, the downlink ports can be 10/100 
PoE ports, 10/100 ports, or 10/100/1000 ports.
You can set these ports for speed and duplex autonegotiation, in compliance with 
IEEE 802.3ab, to optimize port bandwidth. 
If the connected device also supports autonegotiation, the switch port negotiates 
the best connection (the fastest line speed that both devices support and 
full-duplex transmission if the attached device supports it) and configures itself 
accordingly. The default setting is autonegotiate.
The ports also have the automatic-medium-dependent interface crossover 
(auto-MDIX) capability to automatically detect the required cable connection 
type (straight-through or crossover) and to configure the connection 
appropriately.