Section 2-1. Catalyst Switch Families


2-1. Catalyst Switch Families

The family of Catalyst switches is an ever-expanding clan. Starting with the acquisition of Grand Junction, Kalpana, and Crescendo in the mid 1990s and with the addition of Granite in 1999, Cisco Systems has put together some of the finest switching engineers in the world. The result it a family of switching products that offer a variety of features for deployment in campus networks.

One of the major challenges in choosing and deploying a switch in your network is understanding what functions that switch performs and how it functions within the network design. The purpose of this section is to give you a brief overview of the current Catalyst switch platforms and their basic functionalities. In addition, a brief section describes the operating systems supported on the various platforms.

Catalyst 3500XL and 2900MXL Series

The Catalyst 3500XL and 2900MXL series switches provide basic connectivity for end-user devices. These switches are referred to as access switches and vary in port density from 12 ports to 48 ports. The 3500XL series switches support gigabit interface connectors for gigabit uplinks. The 2900MXL is a modular switch that can support a variety of modular connections including an ATM LAN emulation client (LEC) for connectivity to an ATM LANE network. These switches offer a reasonable cost solution for access into a switched network and offer Layer 2 forwarding capabilities with features such as limited quality of service (QoS) classification and scheduling, trunking capabilities, and EtherChannel capabilities. In addition, you can cluster many of these switches for management purposes.

Catalyst 2950 Series

The Catalyst 2950 series switch is a switch that typically provides end-user access, but offers advanced features. The 2950 comes in a variety of port densities, with some options for media speeds and connectors. One of the 2950 products offers 10/100/1000 mbps connectivity using copper. This switch allows for deployment of gigabit to the access layer. The 2950 offers Layer 2 forwarding and has many of the same capabilities as the Catalyst XL series switches, such as trunking and EtherChannel capabilities. The 2950 also adds Layer 3 and Layer 4 security using VLAN access control lists (ACLs), and enhanced QoS classification and scheduling based on Layer 3 and Layer 4 information. The 2950 is the next generation of access switches for the campus network.

Catalyst 3550 Series

The Catalyst 3550 is a midline switch that can offer Layer 2 services or both Layer 2 and Layer 3 services in the same device, depending on the software. The switch comes in different port densities and offers Fast Ethernet and Gigabit Ethernet support. This switch has ports that can be directly configured as Layer 3 interfaces, or can use virtual (VLAN) interfaces for Layer 3 switching. It also supports Layer 2 functionalities on a port-by-port basis for basic Layer 2 connectivity and enhanced features such as trunking, channeling, QoS classification and marking, in addition to access control for Layer 2 or Layer 3 ports.

Because of its flexibility, the 3550 makes an excellent switch in small to midsize campus environments and can be deployed as an access switch or a distribution switch. The 3550 has replaced the 2948G-L3 switch as a midsized wire-speed Layer 3 switch. The 3550 can run either the standard multilayer software image (SMI) for Layer 2 switching or the enhanced multilayer software image (EMI) for Layer 2 and 3 switching.

Catalyst 5000 Series

The Catalyst 5000 series switches are some of the staples of Cisco campus switching. This switch is a modular product that offers both a variety of media support and port densities. The 5000 series consists of the 5000 products and 5500 products. The 5500 switches have been used in many networks as distribution and backbone switches, but are now being deployed as access and distribution switches because of the backplane limitations. The switch supports ATM, FDDI, Token Ring, Ethernet, Fast Ethernet, and Gigabit Ethernet modules in addition to routing and WAN modules for connectivity. The 5500 products offer advanced features such as supervisor redundancy and multilayer switching capabilities. These switches also offer some basic QoS classification and scheduling services.

Catalyst 4000 Series

The Catalyst 4000 series switch is a midline switch that can act as a high-port-density access switch and distribution switch as well as a low-density core device. The 4000 series is also a modular switch that offers both Layer 2 and Layer 3 services. This switch offers Ethernet connectivity and a Layer 3 module. The Supervisor III for the 4000 series has an integrated Layer 3 module and can run Cisco IOS Software. These switches also perform Layer 2 trunking functions and provide support for EtherChannels. The 4000 series switch offers some basic QoS classification and scheduling.

Catalyst 6000 Series

The Catalyst 6000 series switch is the flagship of the Catalyst product lines. It is the most robust, has the highest backplane support, and is the most flexible of any of the Catalyst products. This modular switch can act as a high-port-density access switch, as a Layer 2/Layer 3 distribution switch, and as a wire-speed Layer 2 or Layer 3 core switch. In addition to its high-speed Ethernet switching capabilities, it offers a variety of cards to support advanced features such as voice services, content switching, intrusion detection, network analysis, optical services, 10 Gigabit Ethernet, firewall support, and encryption services. All these features function at wire speeds. In addition to these services, the 6500 chassis support connectivity for the fabric module to interconnect the cards rather than the 32 gbps backplane. With this fabric module, a 6509 or 6513 fully populated with fabric-enabled cards has a total of 256 gbps of fabric connectivity. The switch also offers support for redundancy and high-availability features. The Catalyst 6000 series switches continue to evolve as new products provide more flexibility and functionality.

NOTE

Although Cisco officially announced May 15, 2002, as the end of sales for the Catalyst 6006 and 6009 chassis, it is important to note that the only difference in a 6000 chassis and a 6500 chassis is connectors for fabric cards. The chassis themselves offer no enhanced services without the appropriate cards and modules. Therefore, a 6500 without a fabric module and fabric-enabled cards operates the same as a Catalyst 6000 would. To speak of the products in a generic sense, this text refers to the family as the 6000 series.


Switch Operating Systems

Because the variety of Catalyst products that exist are the direct result of acquisitions, mergers, and ongoing developments, it is not hard to believe that there is also a variety of operating systems (OSs) that configure and manage these devices. A major challenge when working with Cisco switches is understanding the difference between the OSs and how to go about configuring the same functionality on the different platforms. A main purpose of this book is to identify the necessary steps to configure a feature and to distinguish how those steps vary among the different operating systems. Before you can configure these OSs, it is import to be able to differentiate between how the systems work on the different platforms.

The Cisco switch product lines consist of two major OSs. The first is the Cisco Internetwork Operating System (Cisco IOS). This OS is based on the same Kernel and shell used for routers. In the switch world, this OS has three derivatives:

  • Layer 2 IOS This is Cisco IOS that runs on a device that forwards packets based on Layer 2 information only. Some example devices that run Layer 2 IOS include the 3500XL and the 2950.

  • Layer 3 IOS Layer 3 IOS runs on a switch device that performs Layer 3 packet forwarding for its interfaces. This OS is the same that runs on a router; in the switch environment, however, it is found on the 2948G-L3 products, the Route Switch Module (RSM) and Multilayer Switch Module (MSM), and the Route Switch Feature Card (RSFC) and Mutilayer Switch Feature Card (MSFC).

  • Layer 2/Layer 3 IOS This is an IOS that runs on a device that can have a port that acts like a router port (Layer 3) or like a switch port (Layer 2) depending on the device's configuration. The Layer 2/Layer 3 IOS is sometimes referred to as integrated IOS because it integrates the functions of both Open System Integration (OSI) layers. The 3550 runs this OS. This OS can also be run on a 4000 series switch with a Supervisor III card or a 6000 series switch with a MSFC. When the code runs on one of these platforms, it is also referred to as native or Supervisor IOS.

The IOS flavors are similar in command structure, configuration steps, and system management; but they do differ slightly in support and some configuration parameters. Where this is the case, this book points out the differences between the OSs.

The other major OS for the Catalyst family of switches is the Catalyst Operating System (COS), sometimes referred to as CatOS. This OS offers only Layer 2 support and runs on the 4000, 5000, and 6000 series switches. COS is very popular for Layer 2 switching because of the ease of use in its command structure. Table 2-1 shows the different OSs and the platforms that support them.

Table 2-1. OS Platform Matrix

OS

Cisco IOS

Catalyst OS

OSI Layer Support

Layer 2 only

Layer 3 only

Layer 2 and Layer 3

Layer 2 only

Platform

2900MXL

3500XL

2950

2948G-L3

4980G-L3

RSM/MSM

RSFC/MSFC

All routers

Layer 3 services module

3550

4000 series[1]

6000 series[2]

5000 series

4000 series

6000 series


[1] The Catalyst 4000 series switch requires a Supervisor III to run the integrated (Supervisor) IOS.

[2] The Catalyst 6000 series switch requires a supervisor with a MSFC to run the integrated (Supervisor) IOS.

A variety of Cisco switches and OSs will be used for the design and configuration of a campus network based on Cisco products. While using this book, keep in mind which OS and which platform you are using.



Cisco Field Manual. Catalyst Switch Configuration
Cisco Field Manual. Catalyst Switch Configuration
ISBN: 1587050439
EAN: N/A
Year: 2001
Pages: 150

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