Catalyst 2950-12 switch—12 10/100 Ethernet ports
Catalyst 2950-24 switch—24 10/100 Ethernet ports
Catalyst 2950C-24 switch—24 10/100 Ethernet ports and 2 100BASE-FX ports
Catalyst 2950G-12-EI—12 10/100 Ethernet ports and 2 Gigabit Interface Converter (GBIC) module slots
Catalyst 2950G-24-EI—24 10/100 Ethernet ports and 2 GBIC module slots
Catalyst 2950G-24-EI-DC—24 10/100 Ethernet ports and 2 GBIC module slots with direct current (DC)-input power
Catalyst 2950G-48-EI—48 10/100 Ethernet ports and 2 GBIC module slots
Catalyst 2950SX-24 switch—24 10/100 Ethernet ports and 2 1000BASE-SX ports
Catalyst 2950T-24 switch—24 10/100 Ethernet ports and 2 10/100/1000 Ethernet ports
On Catalyst 2950G-12-EI, 2950G-24-EI, 2950G-24-EI-DC, and 2950G-48-EI switches, support for these GBIC modules:

: 1000BASE-SX GBIC
: 1000BASE-LX/LH GBIC
: 1000BASE-ZX GBIC
: 1000BASE-T GBIC (model WS-5483)
: Coarse Wave Division Multiplexer (CWDM) fiber-optic GBIC
: GigaStack GBIC

Configuration

For 10/100 ports, autonegotiates the speed and duplex settings
For 10/100/1000 ports, autonegotiates the speed and supports only full-duplex mode
For 100BASE-FX ports, supports only 100-Mbps and full-duplex settings
For 1000BASE-SX ports, supports only 1000-Mbps and full-duplex settings
Supports 8192 MAC addresses
Checks for errors on a received packet, determines the destination port, stores the packet in shared memory, and then forwards the packet to the destination port

Power redundancy

Connection for an optional Cisco RPS 300 Redundant Power System (RPS) that uses alternating current (AC) input and supplies DC output to the switch

Front-Panel Description

The switch front panel contains the ports, the LEDs, and the Mode button. Figure 1-1 to Figure 1-9 show the switches.

Figure 1-1: Catalyst 2950-12 Switch

Figure 1-2: Catalyst 2950-24 Switch

Figure 1-3: Catalyst 2950C-24 Switch

Figure 1-4: Catalyst 2950G-12-EI Switch

Figure 1-5: Catalyst 2950G-24-EI Switch

Figure 1-6: Catalyst 2950G-24-EI-DC Switch

Figure 1-7: Catalyst 2950G-48-EI Switch

Figure 1-8: Catalyst 2950SX-24 Switch

Figure 1-9: Catalyst 2950T-24 Switch

10/100 Ports

The 10/100 ports use RJ-45 connectors and twisted-pair cabling. The ports can connect to these devices:

10BASE-T devices, such as workstations and hubs, through standard RJ-45 connectors and two twisted-pair cabling. You can use Category 3, 4, or 5 cabling.
100BASE-TX devices, such as high-speed workstations, servers, hubs, routers, and other switches, through standard RJ-45 connectors and two or four twisted-pair, Category 5 cabling.

Note When connecting the switch to workstations, servers, and routers, be sure that the cable is a twisted-pair straight-through cable. When connecting the switch to hubs or other switches, use a twisted-pair crossover cable. Pinouts for the cables are described in "Connectors and Cables."

The 10/100 ports can be explicitly set to operate in any combination of half duplex, full duplex, 10 Mbps, or 100 Mbps. They can also be set for speed and duplex autonegotiation, compliant with IEEE 802.3U. In all cases, the cable length from a switch to an attached device cannot exceed 328 feet (100 meters).

When set for autonegotiation, a port senses the speed and duplex settings of the attached device and advertises its own capabilities. If the attached device supports autonegotiation, the 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.

10/100/1000 Ports

The 10/100/1000 ports on the Catalyst 2950T-24 switches use RJ-45 connectors and twisted-pair cabling. The ports can connect to these devices:

10BASE-T devices, such as workstations and hubs, through standard RJ-45 connectors and two or four twisted-pair, Category 5 cabling.
100BASE-TX devices, such as high-speed workstations, servers, hubs, routers, and other switches, through standard RJ-45 connectors and two or four twisted-pair, Category 5 cabling.
1000BASE-T devices, such as high-speed workstations, servers, hubs, routers, and other switches, through standard RJ-45 connectors and four twisted-pair, Category 5 cabling.

Note When connecting the switch to a 1000BASE-T device, be sure to use a four twisted-pair, Category 5 cable.

Note When connecting the switch to workstations, servers, and routers, be sure to use a twisted-pair straight-through cable. When connecting the switch to hubs or other switches, use a twisted-pair crossover cable. Pinouts for the cables are described in "Connectors and Cables."

The 10/100/1000 ports on the Catalyst 2950T-24 switches can be explicitly set to operate at 10, 100, or 1000 Mbps but only in full-duplex mode. They can also be set for speed autonegotiation, compliant with IEEE 802.3AB. In all cases, the cable length from a switch to an attached device cannot exceed 328 feet (100 meter).

100BASE-FX and 1000BASE-SX Ports

The 100BASE-FX and 1000BASE-SX ports both use 50/125- or 62.5/125-micron multimode fiber-optic cabling. The 100BASE-FX ports operate only at 100 Mbps in full-duplex mode, and the 1000BASE-SX ports operate only at 1000 Mbps in full-duplex mode.

In full-duplex mode, the cable length from a switch to an attached device cannot exceed 1804 feet (550 meters).

You can connect a 100BASE-FX or 1000BASE-SX 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 1-1. Use the Cisco part numbers in Table 1-1 to order the patch cables that you need.

Table 1-1: MT-RJ Patch Cables for 100 BASE-FX and 1000BASE-SX Connections

Type	Cisco Part Number
1-meter, MT-RJ-to-SC multimode cable	CAB-MTRJ-SC-MM-1M
3-meter, MT-RJ-to-SC multimode cable	CAB-MTRJ-SC-MM-3M
5-meter, MT-RJ-to-SC multimode cable	CAB-MTRJ-SC-MM-5M
1-meter, MT-RJ-to-ST multimode cable	CAB-MTRJ-ST-MM-1M
3-meter, MT-RJ-to-ST multimode cable	CAB-MTRJ-ST-MM-3M
5-meter, MT-RJ-to-ST multimode cable	CAB-MTRJ-ST-MM-5M

GBIC Module Ports

The GBIC module slots support these modules:

1000BASE-SX GBIC module for fiber-optic connections that cannot exceed 1804 feet (550 meter).

1000BASE-LX/LH GBIC module for fiber-optic connections that cannot exceed 32,810 feet (10 kilometer).

1000BASE-ZX GBIC module for fiber-optic connections that cannot exceed 328,100 feet (100 kilometer).

1000BASE-T GBIC module for copper connections that cannot exceed 328 feet (100 meter).

CWDM GBIC module for single-mode fiber-optic connections that cannot exceed 393,719 feet (120 kilometer).

GigaStack GBIC module for creating a 1-Gbps stack configuration of up to nine supported switches. The GigaStack GBIC supports one full-duplex link (in a point-to-point configuration) or up to nine half-duplex links (in a stack configuration) to other Gigabit Ethernet devices. Using the required Cisco proprietary signaling and cabling, the GigaStack GBIC-to-GigaStack GBIC connection cannot exceed 3 feet (1 meter).

Note Cisco-approved GBIC modules have a serial EEPROM that contains the module serial number, the vendor name and ID, a unique security code, and cyclic redundancy check (CRC). When a GBIC module is inserted in the switch, the switch software reads the EEPROM to check the serial number, vendor name, and vendor ID and recomputes the security code and CRC. If the serial number, the vendor name or ID, security code, or CRC is invalid, the switch places the interface in an error-disabled state.

Note If you are using a non-Cisco approved GBIC module, remove the GBIC module from the switch, and replace it with a Cisco-approved module.

For more information about these GBIC modules, refer to your GBIC documentation.

LEDs

You can use the LEDs to monitor switch activity and performance. Figure 1-10, Figure 1-11, and Figure 1-12 show the location of the LEDs and the Mode button that you use to select the port mode. Changing the port mode changes the information provided by each port status LED.

All of the LEDs described in this section except the utilization meter (UTIL) are visible in the Cluster Management Suite (CMS). The switch software configuration guide describes how to use CMS to configure and monitor individual switches and switch clusters.

Figure 1-10: LEDs on Catalyst 2950-12, 2950-24, 2950C-24, 2950SX-24, and 2950T-24 Switches

Figure 1-11: LEDs on Catalyst 2950G-12-EI, 2950G-24-EI, and 2950G-24-EI-DC Switches

Figure 1-12: LEDs on Catalyst 2950G-48-EI Switches

System LED

The system LED shows whether the system is receiving power and functioning properly. Table 1-2 lists the LED colors and meanings.

Table 1-2: System LED

Color	System Status
Off	System is not powered up.
Green	System is operating normally.
Amber	System is receiving power but is not functioning properly.

For information about the system LED colors during the power-on self-test (POST), see the "Running POST" section.

RPS LED

The RPS LED shows the RPS status. Table 1-3 lists the LED colors and meanings.

Table 1-3: RPS LED

Color	RPS Status
Off	RPS is off or is not installed.
Solid green	RPS is connected and ready to provide back-up power.
Flashing green	RPS is connected but is unavailable because it is providing power to another device (redundancy has been allocated to a neighboring device).
Solid amber	RPS is in standby mode or in a fault condition. Press the Standby/Active button on the RPS, and the LED should turn green. If it does not, the RPS fan could have failed. Contact Cisco Systems.
Flashing amber	The internal power supply in a switch has failed, and the RPS is providing power to the switch (redundancy has been allocated to this device).

For more information about the Cisco RPS 300, refer to the Cisco RPS 300 Redundant Power System Hardware Installation Guide.

Port Mode and Port Status LEDs

Each port has a port status LED, also called a port LED. These LEDs, as a group or individually, display information about the switch and the individual ports. The port modes (see Table 1-4) determine the type of information displayed.

Table 1-4: Port Mode LEDs

Mode LED	Port Mode	Description
STAT	Port status	The port status. This is the default mode.
UTIL	Switch utilization	The current bandwidth in use by the switch.
DUPLX	Port duplex mode	The port duplex mode: half duplex or full duplex.
SPEED	Port speed	The port operating speed: 10 or 100 Mbps for 10/100 ports and 10, 100, or 1000 Mbps for 10/100/1000 ports.

To select or change the port mode, press the Mode button (see Figure 1-13, Figure 1-14, and Figure 1-15) to highlight the mode that you want. Release the button to enable the highlighted mode.

Figure 1-13: Changing the Port Mode on Catalyst 2950-12, 2950-24, 2950C-24, 2950SX-24, and 2950T-24 Switches

Figure 1-14: Changing the Port Mode on Catalyst 2950G-12-EI, 2950G-24-EI, and 2950G-24-EI-DC Switches

Figure 1-15: Changing the Port Mode on Catalyst 2950G-48-EI Switches

When you change the port mode, the meanings of the port LED colors change. Table 1-5 explains how to interpret these colors.

Table 1-5: Meaning of Port LED Colors in Different Modes

Port Mode	Color	Meaning
STAT (port status)	Off	No link.
	Solid green	Link present.
	Flashing green	Activity. Port is transmitting 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 not forwarding. Port was disabled by management, an address violation, or Spanning Tree Protocol (STP). Note After a port is reconfigured, the port LED can remain amber for up to 30 seconds while STP checks the switch for possible loops.
UTIL (utilization)	Green	The current backplane utilization that is displayed over the amber LED background on a logarithmic scale.
	Amber	The maximum backplane utilization since the switch was powered on.
	Green and amber	See Figure 1-16 to Figure 1-19 for details. Note If the current utilization exceeds the maximum utilization, the maximum utilization is automatically updated.
DUPLX	Off	Port is operating in half duplex.
(half or full duplex)	Green	Port is operating in full duplex.
SPEED (speed)	10/100 ports
	Off	Port is operating at 10 Mbps.
	Green	Port is operating at 100 Mbps.
	10/100/1000 ports
	Off	Port is operating at 10 Mbps.
	Green	Port is operating at 100 Mbps.
	Flashing green	Port is operating at 1000 Mbps.
	1000BASE-X GBIC module ports
	Off	Port is not operating.
	Green	Port is operating at 1000 Mbps.

For more information about GBIC LEDs, refer to your GBIC documentation.

Figure 1-16 to Figure 1-19 show the bandwidth utilization percentages displayed by the right-most LEDs.

If all LEDs on Catalyst 2950-12, 2950-24, 2950C-24, 2950SX-24, and 2950T-24 switches are green (no amber showing), the switch is using 50 percent or more of the total bandwidth. If the far-right LED is off, the switch is using more than 25 but less than 50 percent of the total bandwidth, and so on. If only the far-left LED is green, the switch isp using less than 0.0488 percent of the total bandwidth. (See Figure 1-16.)

If all LEDs on Catalyst 2950G-12-EI switches are green (no amber showing), the switch is using 50 percent or more of the total bandwidth. If the LED for GBIC module slot 2 is off, the switch is using more than 25 but less than 50 percent of the total bandwidth. If LEDs for both GBIC module slots are off, the switch is using less than 25 percent of the total bandwidth, and so on. (See Figure 1-17.)

If all LEDs on Catalyst 2950G-24-EI and 2950G-24-EI-DC switches are green (no amber showing), the switch is using 50 percent or more of the total bandwidth. If the LED for GBIC module slot 2 is off, the switch is using more than 25 but less than 50 percent of the total bandwidth. If LEDs for both GBIC module slots are off, the switch is using less than 25 percent of the total bandwidth, and so on. (See Figure 1-18.)

If all LEDs on Catalyst 2950G-48-EI switches are green (no amber showing), the switch is using 50 percent or more of the total bandwidth. If the LED for GBIC module slot 2 is off, the switch is using more than 25 but less than 50 percent of the total bandwidth. If LEDs for both GBIC module slots are off, the switch is using less than 25 percent of the total bandwidth, and so on. (See Figure 1-19.)

Figure 1-16: Bandwidth Utilization on Catalyst 2950-12, 2950-24, 2950C-24, 2950SX-24, and 2950T-24 Switches

Figure 1-17: Bandwidth Utilization on Catalyst 2950G-12-EI Switches

Figure 1-18: Bandwidth Utilization on Catalyst 2950G-24-EI and 2950G-24-EI-DC Switches

Figure 1-19: Bandwidth Utilization on Catalyst 2950G-48-EI Switches

Rear-Panel Description

Other than the Catalyst 2950G-24-EI-DC switch, the rear panel of a Catalyst 2950 switch has an AC power connector, an RPS connector, and an RJ-45 console port. (See Figure 1-20 and Figure 1-21.)

The rear panel of the Catalyst 2950G-24-EI-DC switch has a DC power connector (also referred to as the terminal block header), a DC ground lug, an RPS connector, and an RJ-45 console port. (See Figure 1-22.)

Figure 1-20: Catalyst 2950 Switch Rear Panel

Figure 1-21: Catalyst 2950G-48-EI Switch Rear Panel

Figure 1-22: Catalyst 2950G-24-EI-DC Switch Rear Panel

Caution You must connect the Catalyst 2950G-24-EI-DC switch only to a DC-input power source that has an input supply voltage from -36 to -72 VDC. If the supply voltage is not in this range, the switch might not operate properly or might be damaged.

Cisco RPS Connector

The RPS is a 300W redundant power system that can support six external network devices and provides DC 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 that device, preventing loss of network traffic.

Warning Attach only the Cisco RPS 300 (model PWR300-AC-RPS-N1) to the RPS receptacle.

For more information about the Cisco RPS 300, refer to the documentation that came with the RPS 300.

Console Port

You can connect a switch to a PC through the console port and the supplied RJ-45-to-DB-9 adapter cable. If you want to connect a switch 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=) with that adapter from Cisco. For console-port and adapter-pinout information, see the "Cable and Adapter Specifications" section.

Management Options

Catalyst 2950 switches offer these management options:

Cluster Management Suite (CMS)

: CMS is made up of three web-based applications that you use to manage switches. You can use Cluster Builder, which includes Cluster View, and Cluster Manager to create, configure, and monitor switch clusters. You can also use Device Manager to manage individual and standalone switches. For more information, refer to the switch software configuration guide and the CMS online help.

IOS command-line interface (CLI)

: You can manage switches by using command-line entries. To access the CLI, connect a PC or terminal directly to the console port on the switch rear panel. If the switch is attached to your network, you can use a Telnet connection to manage the switch from a remote location. For more information, refer to the switch command reference.

CiscoView application

: You can use the CiscoView device-management application to set configuration parameters and to view switch status and performance information. This application, which you purchase separately, can be a standalone application or part of an Simple Network Management Protocol (SNMP) network-management platform. For more information, refer to the documentation that came with your CiscoView application.

SNMP network management

: You can manage switches by using an SNMP-compatible management station running platforms such as HP OpenView and SunNet Manager. The switch supports a comprehensive set of MIB extensions and MIB II, the IEEE 802.1D bridge MIB, and four Remote Monitoring (RMON) groups. For more information, refer to the documentation that came with your SNMP application.

Cisco Intelligence Engine 2100 (IE 2100)

The 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. For more information, refer to the switch software configuration guide and the documentation that came with your application.

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