Catalyst 4948 Install Guide
- Updated:
- February 18, 2018
Chapter: Product Overview
Product Overview
This chapter describes the Catalyst 4948 switch, as well as system features and components.
Catalyst 4948 Switch Applications
The Catalyst 4948 switch (see Figure 1-1) is designed for high-performance, high-density edge switching applications. It is a fixed configuration switching solution delivering 10/100/1000 connectivity on all ports, supporting hot swappable, redundant power supplies in a compact one rack-unit size for applications where space is at a premium.
Figure 1-1 Catalyst 4948 Switch
The Catalyst 4948 switch has a 96-Gbps, nonblocking, full-duplex switching fabric, providing 72 million packets-per-second of switching capacity for high-speed applications. The Catalyst 4948 chassis has 44 10BASE-T/100BASE-TX/1000BASE-T Ethernet ports and four ports that can be either 1000BASE-X SFP ports or 10BASE-T/100BASE-TX/1000BASE-T Ethernet ports.
A removable automatic variable speed fan tray for low noise operation at room temperature and removable and redundant 300 WAC or 300 WDC power supply provides fault-tolerance protection for the switch. See the “Connecting AC Power to the Catalyst 4948 Switch” section.
Catalyst 4948 Switch Software Features
The following is an overview of Catalyst 4948 features:
- Layer 2, Layer 3, and Layer 4 switching services
- Support for 32,768 MAC addresses for Layer 2 switching
- Support for 2,048 VLANs and 4,096 VLAN IDs
–
IEEE 802.1Q VLAN tagging on all ports
– Cisco Inter Switch Link (ISL) tagging on all ports
- 16,000 multicast forwarding entries and 16,000 unicast forwarding entries
- 512 ingress policers and 512 egress policers
- 8,000 ingress Security ACEs and 8,000 egress Security ACEs
- Support for port aggregation using Port Aggregation Protocol (PAgP) for Gigabit EtherChannel
- Catalyst 4500 series management software features include the following:
– Command-line interface (CLI) and Simple Network Management Protocol (SNMP) interfaces consistent with the Catalyst 4500 series switches
– Compatible development of new features with the Catalyst 4500 series switches
– Support for out-of-band management over serial lines through a terminal attached to the console interface
– Support for in-band management through any switch port through SNMP, Telnet client, and Trivial File Transfer Protocol (TFTP)
– Remote Monitoring (RMON) with RMON-1
– Support for standard Layer 2 features: 802.1D Spanning Tree, Cisco Discovery Protocol (CDP), VTP version 2 with pruning extensions, and Cisco Group Management Protocol (CGMP) client
– Full SNMP instrumentation including entity-Management Information Base (MIB), all relevant standard MIBs, and all relevant Cisco MIBs
– Support for the first four RMON groups (Ethernet Statistics, Alarms, Events, and History) on a per-port basis without the need for an optional RMON processing module
Hardware System Features
The Catalyst 4948 switch is a high-performance dedicated Ethernet switch that fully integrates into the Catalyst family of switches using Catalyst 4500 series system software.
The following is an overview of the Catalyst 4948 hardware features:
- 48 10BASE-T/100BASE-TX/1000BASE-T Ethernet ports using RJ-45 interfaces. The following standards are supported:
– IEEE 802.3x Pause and/or Full Duplex
- Four1000BASE-X Ethernet ports using SFP interfaces (These ports share MAC addresses with the last four 10BASE-T/100BASE-TX/1000BASE-T Ethernet ports.)
- Serial console management port using an RJ-45 interface
- A removable automatic variable speed fan tray for low noise operation at room temperature
- Redundant and removable 300 WAC power supplies (DC available)
- 256-MB SDRAM (fixed)
- 64-MB embedded Flash memory
- 96-Gbps switching capacity, 72 million packets-per-second actual forwarding rate
- EtherChannel at 10/100/1000 Mbps
- Hardware-based access lists
- Storm control in hardware
Switch Components
This section describes the Catalyst 4948 hardware components.
Traffic Ports
There are 48 10/100/1000BASE-T Ethernet ports using RJ-45 interfaces and four 1000BASE-X Ethernet ports using SFP interfaces. These SFP ports share MAC addresses with the last four 10/100/1000BASE-T ports. The interface configuration mode command media-type sfp | rj45 command can be used to configure the media type for these ports in the switch software and determines whether the SFP connector or the RJ-45 connector is used. The default is SFP.
Console Port
A console serial port (RJ-45) provides for switch management using standard console equipment. (See Figure 1-2.) A connector pinout table is provided in Appendix A, “Specifications,” for the console and management ports. Use this port when performing Cisco IOS configuration tasks from a console.
The Management port on the front panel is only operational when the switch is in rommon mode. When in use, it offers the same TCP/IP based management services available via inband access ( telnet SNMP etc). IP address configuration via BOOTP is supported on the Management port; it also supports image download to the switch.
Figure 1-2 Detailed View of the LEDs for the Management Port
Figure 1-3 Detailed View of the STATUS LED
Note A console cable is not provided in the accessory kit. It can be ordered as an option.
Front Panel LEDs
The LEDs on the front panel of the Catalyst 4948 switch (see Figure 1-2 and Figure 1-3) provide status information as follows:
- MGT LED indicates the operating state of the console or management connection.
- STATUS LED indicates the operating state of the Catalyst 4948 switch.
- PS1 LED indicates the internal power supply status.
- PS2 LED indicates the internal power supply status.
- FAN LED indicates the fan tray status.
- A link status LED is below the 10BASE-T and 100 BASE-T management port.
A description of the LED functions is provided in Table 1-1 .
|
|
|
|
|---|---|---|
10/100 BASE-T console port is in link-up state 10/100 BASE-T console port is in link-down state or not connected |
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10/100 BASE-T Management port is in link-up state 10/100 BASE-T Management port is in link-down state or not connected |
||
At startup, the Catalyst 4948 performs a series of diagnostic tests: |
||
Port is operational |
||
No power to the switch or fans (the tray may not be plugged in especially if one or more of the power supplies status LED is green) |
||
No power to the PS |
Chassis Cooling
Note For environmental specifications, see Chapter2, “Site Planning”
The hot-swappable system fan tray provides cooling air for the internal chassis components. The fans exhaust air to the rear, and fresh air is drawn in from the sides of the chassis.
When the fan tray is removed, internal circuitry is exposed that should not be touched by tools or fingers. The system should not be left operating without a fan tray for longer than is necessary to replace a faulty fan tray with a new one.
Figure 1-4 shows the direction of airflow going in and out of the switch.
Figure 1-4 Catalyst 4948 Airflow
There are four fans in the fan tray. If an individual fan fails, the other fans continue to run. Sensors monitor the internal air temperatures. The number of fans in operation and their speed varies according to the internal temperature for the quietest operation possible. If the air temperature exceeds a desired threshold, the environmental monitor displays warning messages.
Power Supplies
Note For complete power specifications for the Catalyst 4948 switch, see , “Specifications.”
The Catalyst 4948 switch has two redundant internal 300-WAC or 300-WDC power supplies. PS1 is the primary power supply and PS2 is the redundant power supply. (See Figure 1-5.)
The internal power supplies have individual power cords and status LEDs (PS1 and PS2 on the front panel). There are also LEDs on the power supplies that show status for the input (Input OK) and output (Output OK) currents. A power cord is used to connect the power supplies to the site power source. There is a power switch on the AC Catalyst 4948 switch power supplies; AC power is present when a power cord is plugged into a power supply and the switch is set to the On position. (See Figure 1-6.) DC power supplies do not have an on/off switch.
Figure 1-5 Primary and Redundant Power Supplies
Figure 1-6 On/off Switch Locations
The switch will start with only one power supply plugged in, but redundant failover and load sharing will not be available in this configuration. We recommend that you always connect both power supplies to separate AC or DC circuits for optimal power reliability.
For safety reasons, the AC power supply needs to be switched off and unplugged before it is removed from a chassis or inserted into a chassis. DC supplies should have power shut off from the source before they are removed.
If only one power supply will be used, you must use the blank faceplate supplied to cover the empty power bay.
Environmental Monitoring of the Power Supplies
Using the environmental monitoring and reporting functions, you can maintain normal system operation by resolving adverse environmental conditions prior to loss of operation.
Each power supply monitors its own temperature and output voltages. If conditions reach critical thresholds, the power supply might shut down to avoid damage from excessive heat or electrical current. The Catalyst 4948 switch senses the operating condition of the power supply and reports status through software.
Power Management for the Catalyst 4948 Switch
You can select from AC or DC power supplies to power your switch. The Catalyst 4948 switch supports the following power supplies:
A redundant power supply can be identified and diagnosed by a running system regardless of its input status. AC and DC supplies are interchangeable.
Power Management Modes
The Catalyst 4948 switch supports the redundant power management mode. In this mode, if both power supplies are operating normally, each provides from 20/80 to 45/55 percent of the total system power requirements at all times. If one power supply fails, the other unit increases power to 100 percent of the total power requirement.
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