Table Of Contents
Product Overview
The Catalyst 3550 family of multilayer switches—also referred to as the switches—are stackable Ethernet switches to which you can connect workstations, Cisco IP Phones, and other network devices such as servers, routers, and other switches. These switches also can be deployed as backbone switches, aggregating Gigabit Ethernet traffic from other network devices.
This chapter provides a functional overview of the Catalyst 3550 switch models. These topics are included:
Features
Figure 1-1 and Figure 1-2 show the Catalyst 3550 switch models, and Table 1-1 describes the switch features.
Figure 1-1 Catalyst 3550-12T and 3550-12G Switch Models
Figure 1-2 Catalyst 3550-24, 3550-24-DC, 3550-FX, 3550-24PWR, and 3550-48 Switch Models
Table 1-1 Switch Features
Hardware
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2 or 10 Gigabit Ethernet 10BASE-T/100BASE-TX/1000BASE-T ports and 2 or 10 GBIC1 -based Gigabit Ethernet slots (Catalyst 3550-12T and 3550-12G switches)
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Configuration
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Power Redundancy
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Inline Power2
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1 Gigabit Interface Converter
2 Only Catalyst 3550-24PWR switch
Front-Panel Description
The switch front panel includes the 10/100 or 10/100/1000 Ethernet ports or 100BASE-FX ports, GBIC module slots, and switch LEDs as shown in Figure 1-3 and described on the following pages.
Note
Figure 1-3 Switch Front Panel
Mode button
10/100 or 10/100/1000 Ethernet ports or 100BASE-FX ports1
Switch LEDs
GBIC slots
Port LEDs
1 Port numbering is from left to right, with port 1 on the far left. For ports grouped in pairs, the first member of the pair (port 1) is above the second member (port 2). The GBIC slots are numbered 1 (left) and 2 (right) or 1 (above) and 2 (below).
10/100 and 10/100/1000 Ports
The Fast Ethernet (10/100-Mbps) and Gigabit Ethernet (10/100/1000-Mbps) ports use standard RJ-45 connectors and Ethernet pinouts with internal crossovers. The maximum cable length is 328 feet (100 meters). 100BASE-TX and 1000BASE-T traffic requires twisted four-pair Category 5 cable. 10BASE-T traffic can use Category 3 or Category 4 cable.
Fast Ethernet ports operate at 10 or 100 Mbps in either full- or half-duplex mode. In full-duplex mode, two stations can send and receive traffic at the same time. Normally, 10-Mbps ports operate in half-duplex mode, which means that stations can either receive or send traffic.
You can configure interface speed on Fast Ethernet and Gigabit Ethernet ports. On Fast Ethernet ports, you can configure the duplex mode to full, half, or autonegotiate. On Gigabit Ethernet ports, you can configure ports to full-duplex mode or to autonegotiate; half-duplex mode is not supported.
The default setting is autonegotiate. At this setting, the port senses the speed and duplex settings of the attached device and advertises its own capabilities. If the connected device also supports autonegotiation, the switch port negotiates the best connection (that is, the fastest line speed that both devices support and full-duplex transmission if the attached device supports it) and configures itself accordingly.
10/100 Inline Power Ports
The 10/100 ports on the Catalyst 3550-24PWR switch provide protocol support for Cisco IP Phones and Cisco Aironet Access Points:
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On a per-port basis, you can control whether or not a Catalyst 3550-24PWR 10/100 port automatically provides power when an IP phone or an access point is connected. There are two inline power settings for each 10/100 port: Auto and Never. When you select the Auto setting for inline power on a port, the port only provides power if an IP phone or an access point is connected to it. The Auto setting is the default. However, when you select the Never setting for inline power on a port, the port does not provide power even if a Cisco IP phone or an access point is connected to it.
100BASE-FX Ports
The 100BASE-FX ports use 50/125- or 62.5/125-micron multimode fiber-optic cabling. In full-duplex mode, the cable length from a switch to an attached device cannot exceed 6,562 feet (2 kilometers).
The 100BASE-FX ports operate only at 100 Mbps in either full- or half-duplex mode and do not support autonegotiation. The half-duplex mode is the default setting.
You can connect a 100BASE-FX port to an SC or ST port on a target device by using one of the MT-RJ fiber-optic patch cables listed in Table B-1.
GBIC Module Slots
You cannot configure speed or duplex mode on GBIC slots, but for certain types of GBICs, you can configure speed to not negotiate (nonegotiate) if connected to a device that does not support autonegotiation.
The GBIC module slots support these modules to provide flexibility in media and distance options:
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Cisco-approved CWDM GBIC modules have a serial EEPROM that contains the module serial number, the vendor name and vendor ID, a unique security code, and cyclic redundancy check (CRC). When a CWDM GBIC module is inserted in the switch, the switch software reads the EEPROM to check the serial number, vendor name and vendor ID, and recompute the security code and CRC. If the serial number, the vendor name or vendor ID, the security code, or CRC is invalid, the switch places the port in an error-disabled state.
For more information about GBICs, see the documentation included with your GBIC module and Related Publications, for a list of related documentation.
LEDs
You can use the switch LEDs to monitor switch activity and its performance. Figure 1-3 shows the LEDs and the Mode button that you use to select one of the port modes.
All of the LEDs described in this section except the utilization meter (UTIL) are visible on the device manager and through the Network Assistant.
System LED
The system LED shows whether the system is receiving power and is functioning properly. Table 1-2 lists the LED colors and their meanings.
Table 1-2 System LED
Off
System is not powered on.
Green
System is operating normally.
Amber
System is receiving power but is not functioning properly.
RPS LED
The RPS LED shows the RPS status. Table 1-3 lists the LED colors and their meanings.
For more information about the Cisco RPS 300 or the Cisco RPS 675, see the documentation included with the RPS.
Port LEDs and Modes
Each RJ-45 port and GBIC module slot has a port LED. These port LEDs, as a group or individually, display information about the switch and about the individual ports. The port mode determines the type of information displayed through the port LEDs. Table 1-4 lists the mode LEDs and their associated port modes and meanings.
To select or change a mode, press the Mode button (or Mode label on the Catalyst 3550-48 switch) until the desired mode is highlighted. When you change port modes, the meanings of the port LED colors also change. Table 1-5 explains how to interpret the port LED colors in different port modes.
You can also use the Mode button to activate the Express Setup program or to clear the switch IP address and all switch settings. See the "Clearing the Switch IP Address and Configuration" section for more information.
Table 1-4 Port Mode LEDs
STATUS
Port status
The port status. This is the default mode.
UTIL1
Switch utilization
The current bandwidth in use by the switch. (See Figure 1-4 through Figure 1-8.)
DUPLX
Port duplex mode
The port duplex mode: full duplex or half duplex.
SPEED
Port speed
The port operating speed: 10, 100, or 1000 Mbps.
LINE PWR2
Port inline power
The inline power status: on or off.
1 Not available on Catalyst 3550-24PWR switches
2 Available only on Catalyst 3550-24PWR switches
Table 1-5 Meaning of LED Colors in Different Modes
STATUS
(port status)Off
No link, or port was administratively shut down.
Solid green
Link present.
Blinking green
Activity. Port is sending or receiving data.
Alternating green-amber
Link fault. Error frames can affect connectivity, and errors such as excessive collisions, CRC errors, and alignment and jabber errors are monitored for a link-fault indication.
Solid amber
Port is blocked by Spanning Tree Protocol (STP) and is not forwarding data.
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Blinking amber
Port is blocked by STP and is sending or receiving packets.
UTIL1
(utilization)Green
Port LEDs display backplane utilization on a logarithmic scale. (See Figure 1-4 through Figure 1-8.)
Amber
Peak total backplane utilization over the last 24 hours.
DUPLX
(duplex)Off
Port is operating in half duplex.
Green
Port is operating in full duplex.
SPEED
Off
Port is operating at 10 Mbps.
Green
Port is operating at 100 Mbps.
Blinking green
Port is operating at 1000 Mbps.
Off
Port is not operating.
Blinking green
Port is operating at 1000 Mbps.
LINE PWR2
Off
Inline power is off.
Green
Inline power is on.
If the Cisco IP Phone is receiving power from an AC power source, the port LED is off even if the IP phone is connected to the switch port. The LED turns green only when the switch port is providing power.
1 Not available on Catalyst 3550-24PWR switches
2 Available only on Catalyst 3550-24PWR switches
Bandwidth Utilization
The UTIL mode on the switch shows the current bandwidth in use by the switch. (See Figure 1-4 to Figure 1-8.) If all possible port LEDs are green, bandwidth utilization is in the 50 to 100 percent range. Every port LED that is off (black) divides this range by two.
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Figure 1-4 shows the bandwidth utilization percentages displayed by the LEDs on the Catalyst 3550-12T switch.
Figure 1-4 Bandwidth Utilization for the Catalyst 3550-12T
Figure 1-5 shows the bandwidth utilization percentages displayed by the LEDs on the Catalyst 3550-12G switch.
Figure 1-5 Bandwidth Utilization for the Catalyst 3550-12G
Figure 1-6 shows the bandwidth utilization percentages displayed by the LEDs on the Catalyst 3550-24 and 3550-24-DC switches.
Figure 1-6 Bandwidth Utilization for the Catalyst 3550-24 and 3550-24-DC
Figure 1-7 shows the bandwidth utilization percentages displayed by the LEDs on the Catalyst 3550-48 switch.
Figure 1-7 Bandwidth Utilization for the Catalyst 3550-48
Figure 1-8 shows the bandwidth utilization percentages displayed by the LEDs on the Catalyst 3550-24-FX switch.
Figure 1-8 Bandwidth Utilization for the Catalyst 3550-24-FX
Rear-Panel Description
Other than the Catalyst 3550-24-DC switch, the switch rear panels have an AC power connector, an RPS connector, and an RJ-45 console port, which are shown in Figure 1-9 and described in this section.
The rear panel of the 3550-24-DC switch has a DC power connector (also referred to as the terminal block header), an RJ-45 console port, and a ground lug. The switch is shipped with a terminal block plug in the DC power connector.
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Figure 1-9 Switch Rear Panel
AC Power Connector
For AC-powered switches, the internal power supply is an autoranging unit that supports input voltages between 100 and 240 VAC.
For the Catalyst 2440-24-DC power information, see "DC Power Connections."
Cisco RPS Connector
For protection against a power supply failure, you can connect a Cisco RPS to the switch. The Cisco RPS can support six external network devices and provide power to one failed device at a time. It automatically senses when the internal power supply of a connected device fails and provides power to the failed device, preventing loss of network traffic.
The Cisco RPS 300 has two output levels: -48 V and 12 V with a total maximum output power of 300 W. The Cisco RPS 675 has two output levels: -48 V and 12 V with a total maximum output power of 675 W.
These Cisco RPS models support the Catalyst 3550 switches:
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Catalyst 3550-12T, 3550-12G, 3550-24, 3550-FX, and 3550-48 switches.•
Catalyst 3550-12T, 3550-12G, 3550-24, 3550-FX, 3550-24PWR, and 3550-48 switches.The Cisco RPS 300 does not support the Catalyst 3550-24-DC or 3550-24PWR switch. The Cisco RPS 675 does not support the Catalyst 3550-24-DC switch.
The RPS 300 and RPS 675 models also support other Cisco devices. See the RPS documentation for more information.
Console Port
You can connect the switch to a PC by using the console port and the supplied RJ-45-to-DB-9 adapter cable. If you want to connect the switch console port to a terminal, you need to provide an RJ-45-to-DB-25 female DTE adapter. You can order a kit (part number ACS-DSBUASYN=) containing that adapter from Cisco.
Management Options
The Catalyst 3550 switches offer several management options:
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You can use the device manager, which is in the switch memory, to manage individual and standalone switches. The device manager is accessible after you have run the Express Setup program (see the getting started guide for more information about running Express Setup). Use the device manager to perform basic switch configuration and monitoring. You can access the device manager from anywhere in your network through a web browser.
To launch the device manager, enter the switch IP address in the web browser, and press Enter. The device manager page appears.
See the device manager online help for more information.
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The switch CLI is based on Cisco IOS software and is enhanced to support desktop-switching features. You can fully configure and monitor the switch and switch cluster members from the CLI. You can access the CLI either by connecting your management station directly to the switch console port or by using Telnet from a remote management station. See the command reference on Cisco.com for more information.
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SmartPort macros provide a convenient way to save and share common switch configurations. You can use SmartPort macros to enable features and settings based on the location of a switch in the network and for mass configuration deployments across the network.
Cisco provides a collection of pretested, Cisco-recommended baseline SmartPort macros for Catalyst switches. You can use the macros to build and deploy Cisco-recommended network designs and configurations. For more information about SmartPort macros, see the software configuration guide and the SmartPort information available on Cisco.com.
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The CiscoView device-management application displays the switch image that you can use to set configuration parameters and to view switch status and performance information. The CiscoView application, which you purchase separately, can be a standalone application or part of an SNMP platform. See the CiscoView documentation for more information.
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You can manage switches from a SNMP-compatible management station that is running platforms such as HP OpenView or SunNet Manager. The switch supports a comprehensive set of MIB extensions and four Remote Monitoring (RMON) groups. See the software configuration guide on Cisco.com and the documentation that came with your SNMP application for more information.
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Cisco IE200 Series Configuration Registrar is a network management device that works with embedded Cisco Networking Services (CNS) agents in the switch software. You can automate initial configurations and configuration updates by generating switch-specific configuration changes, sending them to the switch, executing the configuration change, and logging the results.
Network Configurations
See the software configuration guide on Cisco.com for network configuration concepts and examples.
