Cisco - Cisco Catalyst 2940 Series Switches Q and A

The Cisco Catalyst 2940 Series switches are small, standalone, managed switches with eight Fast Ethernet ports and a single integrated Fast Ethernet or Gigabit Ethernet uplink. The switches are designed to be used outside the wiring closet in the end-user workspace, and feature a durable metal shell, no fan for silent operation, easy wall or under-the-desk mounting, a security lock slot to prevent theft, and an available cable guard to secure the Ethernet cables and switch.

The Cisco Catalyst 2940 Series is extremely easy to set up and configure via Cisco Express Setup, a simple Web-based setup utility. For more advanced configuration and ongoing management, the Cisco Catalyst 2940 Series has a console port and supports remote management protocols such as Telnet, Simple Network Management Protocol (SNMP), as well as the Cisco Cluster Management Suite (CMS), which is a free Java-enabled Web-based monitoring and configuration tool that comes embedded in the switch and can manage up to 16 switches at once. Combine this with the rich functionality of Cisco IOSR Software, and these switches provide comprehensive functionality and manageability for classrooms, conference rooms, or other very small workgroup environments.

The Cisco Catalyst 2940 Series is supported by a limited lifetime warranty and free software updates for life to keep the switch current with new standards and technologies. In summary, the Cisco Catalyst 2940 Series switches provide the lowest total cost of ownership in their product class with their durable design, simple installation and management, and award-winning Cisco support.


Product Name	Product Number	Product Description
Cisco Catalyst 2940-8TF	WS-C2940-8TF-S	8 10/100 ports and 1 100FX port and 1 SFP-based 1000BASE-X port
Cisco Catalyst 2940-8TT	WS-C2940-8TT-S	8 10/100 ports and 1 10/100/1000BASE-T port
Cisco Catalyst 2940 Series Cable Guard	CABLEGUARD-C2940=	Cable Guard for the Cisco Catalyst 2940 Series switches that deters theft as well as prevents tampering with Ethernet cable jacks.

Hardware

No. The Cisco Catalyst 2940 was designed for the user environment, not the wiring closet. Thus, the 2940 can be wall-mounted, desk-mounted, or mounted under desks or tables using the mounting template and screws provided in the accessory kit. In addition, a specially-designed magnet for mounting to metal surfaces, such as steel cabinets or desks, is provided in the accessory kit.

The Cisco Catalyst 2940 should be used when it is not feasible or too expensive to pull additional copper or fiber cabling from the wiring closet to satisfy an increased number of end-user devices. By placing a 2940 in a classroom, conference room, cubicle, or very small workgroup environment, network administrators can accommodate up to eight devices, even if there is only a single copper or fiber drop to that location.

The 2940 is also an excellent replacement for small hubs or unmanaged switches because it enables network administrators to have more control over their network, ensure network security, monitor and manage switches remotely, and improve network performance and service levels. All of this reduces the total cost of ownership of their network and improves user productivity.

What about the Cisco Catalyst 2940 that makes it so amenable to the end-user environment, outside of the wiring closet?

The Cisco Catalyst 2940 is ideal for the end-user environment for the following reasons:

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Passive cooling without the use of a fan makes it completely silent and so it is not disruptive in quiet environments.

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A durable all metal shell protects the switch from accidental or intentional physical abuse.

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A mounting kit is provided for wall-mounting, desk-mounting, or under-the-desk mounting. In addition, a specially-designed magnet for mounting to metal surfaces is also provided.

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A separately purchased security cable (as is commonly used with laptops) can be installed in one of the security slots on each side of the switch to prevent theft.

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An optional Cable Guard protects the Ethernet cables from tampering or removal, and also provides further protection against theft.

No. The Cisco Catalyst 2940 does not have a stacking interface and does not support the GigaStack^Ž GBIC.

Do the Cisco Catalyst 2940 switches have Redundant Power Supply (RPS) support?

No. In order to minimize the cost and size of the Cisco Catalyst 2940, there is no support for power supply redundancy.

Uplinks

No. Only one uplink can be used at a time. If no SFP is inserted, the switch will use the 100FX port for the uplink. If an SFP is inserted, the switch will use the 1000BASE-X uplink.

SFPs are transceivers that provide Gigabit Ethernet connectivity from the Cisco Catalyst 2940 switches to wiring closet switches. They are functionally equivalent to Gigabit Interface Converters (GBICs), but are much smaller. Most of the networking industry is moving towards using SFPs instead of GBICs.

Cisco Catalyst 2940 switches support Cisco's 1000BASE-LX/LH, 1000BASE-SX, and 1000BASE-T SFPs (future). Part numbers for these products are GLC-LH-SM= and GLC-SX-MM= respectively.

Do the Cisco Catalyst 2940 switches interoperate with SFPs from other vendors?

No. Like other Cisco switches and routers, the Cisco Catalyst 2940 switches do not interoperate with other vendors' SFPs. The switch will shut down the port if an SFP is inserted that is not a Cisco SFP to avoid the risk of electrical incompatibilities.

What type of fiber connectors are supported on the Cisco Catalyst 2940-8TF switch?

The Cisco Catalyst 2940-8TF supports an MT-RJ connector for the 100BASE-FX port, and an LC connector for the SFP port. For customers that use SC or ST connectors, MTRJ-to-SC and MTRJ-to-ST fiber patch cables are available from Cisco, and some LC-to-SC fiber patch cables are available today but with more coming available soon. The Cisco fiber patch cables currently available are:


Part Number	Description
CAB-MTRJ-SC-MM-1M=	MT-RJ MM to SC Duplex MM - 1 meter
CAB-MTRJ-ST-MM-1M=	MT-RJ MM to ST Duplex MM - 1 meter
CAB-MTRJ-SC-MM-3M=	MT-RJ MM to SC Duplex MM - 3 meter
CAB-MTRJ-ST-MM-3M=	MT-RJ MM to ST Duplex MM - 3 meter
CAB-MTRJ-SC-MM-5M=	MT-RJ MM to SC Duplex MM - 5 meter
CAB-MTRJ-ST-MM-5M=	MT-RJ MM to ST Duplex MM - 5 meter
CSS5-CABLX-LCSC=	10-Meter Fiber Single Mode LX LC-to-SC Connectors
CSS5-CABSX-LC=	10-Meter Fiber Multimode SX LC Connectors
CSS5-CABSX-LCSC=	10-Meter Fiber Multimode SX LC-to-SC Connectors

Software

The Cisco Catalyst 2940 ships with Standard Image (SI) IOS^Ž software only. The SI image offers a robust set of Layer 2 functionality, but not the Layer 3 or Layer 4 intelligent features found in the Cisco Catalyst 2950 EI, 2970, 3550, or 3750 Series.

How is the Cisco Catalyst 2940 Series software different from the Cisco Catalyst 2950 SI software?

The Cisco Catalyst 2940 Series runs nearly the same software as the 2950 SI except there is support for only four Virtual LANs (VLANs) and four corresponding Spanning Tree Protocol (STP) instances. Although only 4 VLANs are supported, the switch supports VLAN IDs ranging from 1-1005. Thus, Cisco Catalyst 2940 switches will work fine in networks that have a large number of VLANs, as long as only 4 VLANs are trunked to the Cisco Catalyst 2940 switch

Does the Cisco Catalyst 2940 software image support voice VLAN so that voice can be managed in its own logical network?

Yes, the Cisco Catalyst 2940 supports voice VLAN. Voice VLAN makes it much easier to deploy IP telephony because a different IP address subnet may be used for the IP phones. In addition, voice VLAN simplifies ongoing management because all of the voice traffic is contained in a separate logical network.

No. IP routing is available in the Cisco Catalyst 6500, 4500, 3750, and 3550 switches.

Since the Cisco Catalyst 2940 software is very similar to the Cisco Catalyst 2950 SI, is there also an Enhanced Image (EI) for the Cisco Catalyst 2940?

No. The Cisco Catalyst 2940 has only one software image. However, several updates to that software image will be provided each year and customers can update their Cisco Catalyst 2940 to take advantage of the new features—thus keeping them current with new standards and technologies as they evolve.

Does the Cisco Catalyst 2940 software image support classification and security based on Layer 3 and Layer 4 information?

No. Layer 3 and Layer 4 lookups are not supported. This functionality is provided in the Cisco Catalyst 6500, 4500, 3750, 3550, 2970 series, as well as the 2950 EI switches.

Security

Rather than configuring the usernames and passwords of network administrators on every single switch, the Cisco Catalyst 2940 supports both RADIUS and TACACS+ authentication servers. Thus, every time network administrators attempt to configure or monitor a switch, they will be prompted to enter their username and password. In large networks, it is more efficient to store the username and password information on a centralized RADIUS or TACACS+ server, instead of on every single switch. In addition, different levels of network administrators or technicians can be provided different levels of authorization, ranging from full configuration capabilities to just read-only capability.

The Cisco Catalyst 2940 supports the IEEE 802.1x standard that works in conjunction with a RADIUS server to authenticate users as they access a network. This functionality provides port-level security and prevents unauthorized users or intruders from accessing the network. A similar Cisco feature is Port Security, which ensures the appropriate PC is on the network by limiting access to the port based on MAC address.

Cisco Private VLAN Edge (PVLAN) is a feature that isolates access ports so that users cannot snoop on the traffic going to other users on the same switch. Any traffic sent on an isolated PVLAN Edge port is directed upstream in the network where it can be filtered using a router or firewall or monitored with an Intrusion Detection System before being sent to another PVLAN isolated port.

Quality of Service

Does the Cisco Catalyst 2940 Series support the appropriate Quality of Service (QoS) mechanisms to support voice, video, and data applications?

Yes, for basic voice, video, and data applications. Support for four queues/port allows network administrators to choose from four different service levels for each type of network traffic. Using the 802.1p Class of Service (CoS) value in the packet header, the Cisco Catalyst 2940 switch can place different types of traffic into different prioritized queues. Queue priorities can be configured using Strict Priority or Weighted Round Robin scheduling. If running voice over the network, it is better to use Strict Priority scheduling, and if there is a mix of video and/or data applications, Weighted Round Robin scheduling is generally preferred.

However, much higher voice and video quality can be achieved by using the Cisco Catalyst 3750, 3550, 2970, or Cisco Catalyst 2950 Enhanced Image switches, all of which provide Intelligent Network Services and more robust quality of service mechanisms. Based on Cisco AVVID (Architecture for Voice, Video and Integrated Data), Cisco also recommends inline power, redundant power, and redundant uplinks to ensure the utmost reliability for the voice network. The 3550-24PWR is typically recommended in such instances if a stackable switch is still appropriate.

Availability

Yes, the Cisco Catalyst 2940 supports IGMP Snooping. This feature makes more efficient use of network bandwidth when using multicast applications. In addition, the Cisco Catalyst 2940 Series supports Immediate Leave processing which prunes out unnecessary multicast traffic more quickly than standard multicast leave processing.

Yes, the Cisco Catalyst 2940 supports not only broadcast storm control, but also unicast and multicast storm control. This feature mitigates the impact of faulty NICs that are sending out massive amounts of unnecessary traffic by blocking the traffic above a certain threshold, shutting down the port, or alerting a network administrator via an SNMP trap.

Yes, the Cisco Catalyst 2940 supports PortFast, which allows PCs to connect more quickly to the network when first connected to the switch—thereby improving user productivity and reducing support calls.

Network Management

Yes. By pressing the mode button for two seconds during switch bootup, the switch will enter Express Setup mode. This allows the user to connect to the switch via Ethernet, launch a Web browser, and complete a single Web page that provides a basic configuration for the switch so that it is remotely manageable. After completing Express Setup, the switch can be connected to the network. This tool is designed for networking novices.

Note: The switch should not be connected to the network when in Express Setup mode because a DHCP server is activated in the switch, and this can cause IP address conflicts.

After I have used Express Setup, can I disable this feature to prevent others from using the Mode Button to enter Express Setup Mode?

Does the Cisco Catalyst 2940 Series support Cisco Switch Clustering technology?

Yes, the Cisco Catalyst 2940 switches can be managed using the Web-based Cisco CMS (CMS) Software, which uses Cisco Switch Clustering technology. Cisco CMS is Web-based software that is embedded in Cisco Catalyst 3750, 3550, 2970, 2955, 2950, 2940, 2950 LRE, as well as the legacy 3500 XL, 2900 XL, 2900 LRE XL, and 1900 Series switches. Through Cisco Switch Clustering technology, users access Cisco CMS with any standard Web browser to manage up to 16 interconnected switches at once, regardless of their geographic proximity and with the option of using a single IP address if desired. The backward compatibility to legacy switches provides a consistent look and feel for managing clusters as customers upgrade networks on a gradual basis, and eliminates the cost of training network administrators on new management tools.

Because Cisco Switch Clustering technology is not limited by proprietary stacking modules, stacking cables or interconnection media, Cisco CMS expands the traditional cluster domain beyond a single wiring closet and lets users mix and match interconnections to meet specific management, performance, and cost requirements.

Cisco CMS also allows the network administrator to designate a standby or redundant command switch, which takes the commander duties should the primary command switch fail. Other important features include the ability to configure multiple ports and switches simultaneously, as well as perform software updates across the entire cluster at once. Bandwidth graphs and link reports provide useful diagnostic information and the topology map gives network administrators a quick view of the network status. The new Guide Mode in Cisco CMS leads the user step-by-step through the configuration of high-end features and provides enhanced online help for context-sensitive assistance. Finally, CMS can enable automated e-mail notification of network errors or issues.

Yes, but only if the members are Cisco Catalyst 2940 switches. Typically, a command switch can only manage members that have a lower number. For example, a 2950 can be a command switch for a 2940, but a 2940 cannot be a command switch for a 2950. Thus, a 2940 command switch can have the following as members: 2940, 2900 XL, 2820, and 1900 Series switches.

Yes. The Cisco Catalyst 2940 Series is supported by a broad range of CiscoWorks products, such as CiscoWorks LAN Management Solution (LMS) and CiscoWorks Access Control Server. For smaller networks, CiscoWorks Small Network Management Solution (SNMS) or CiscoWorks for Windows provide good solutions.

Positioning

The Cisco Catalyst 2940 switches are designed for deployment in user environments beyond the wiring closet. Common deployments are in classrooms, conference rooms, or very small workgroups where it is difficult to pull additional copper or fiber cabling to handle increased port density requirements. The Cisco Catalyst 2940 is also a good fit for very small branch offices with less than eight PCs.

How is the Cisco Catalyst 2940 Series positioned relative to the Cisco Catalyst 2950 Series switches?

Whereas the Cisco Catalyst 2940 switches are designed for the user environment, the Cisco Catalyst 2950 switches are primarily used in the wiring closet. In addition, the 2940 Series has only one software image, while the 2950 Series has some models that run a SI and others that run an EI. The 2940 feature set is very similar to the 2950 SI with two exceptions: only 4 VLANs and 4 STP instances are supported. The Cisco Catalyst 2940 does not have any models with the Intelligent Network Services found in the 2950 EI.

The Cisco Catalyst 2940 provides an excellent replacement for the legacy Cisco 1548M, 1548U, 1538M, and 1538U switches and hubs. All of these have previously been EOS.

While the Cisco Catalyst 2940 has QoS functionality to handle voice traffic, Cisco recommends more advanced QoS functionality, inline power, redundant power, and redundant uplinks to ensure the utmost reliability for an AVVID voice network. The 3550-24PWR is recommended in such instances if a stackable switch is appropriate.

Service and Warranty

Cisco Catalyst 2940 switches come with the Cisco Limited Lifetime Hardware Warranty. Ongoing software updates are available to customers on the Cisco Web site free of charge. Lastly, free access to Cisco Connection Online (CCO) and all of its resources is provided for free.

Limited Lifetime Warranty

The hardware warranty available on Cisco Catalyst 3750, 3550, 2970, 2950, 2940, and 3500/2900 XL is the Limited Lifetime Hardware Warranty. This warranty automatically comes with the purchase of eligible Cisco Catalyst products, free of charge. For specific details on the Limited Lifetime Hardware Warranty, visit:

Software Update

In addition to the Limited Lifetime Hardware Warranty, Cisco is offering ongoing Cisco IOS^Ž Software updates on LAN access switches free of charge for the above platforms. For the life of the product, updates within the release and feature set purchased will be made available to customers through the Software Center at:

This statement supersedes any previous warranty or software statement and is subject to change without notice.

What types of service and support are available for the Cisco Catalyst 2940 Series switches?

A full complement of life-cycle service and support is available for the Cisco Catalyst 2940 Series. From implementation to operation and optimization, Cisco offers Technical Support Service and Advanced Service delivered either directly or through one of its best-in-class partners.

Technical Support Service

Technical Support Service is available through SMARTnet^Ž and SMARTnet Onsite. SMARTnet augments the resources of your operations staff by providing them with access to expertise, both online and on the telephone, and a range of hardware Advance Replacement options. SMARTnet Onsite complements the hardware Advance Replacement feature by adding the services of a field engineer, services that can be critical for those locations where staffing is insufficient or unavailable to perform parts replacement activities. For more information about SMARTnet, visit:

Advanced Service

Total Implementation Solutions (TIS) offers a full range of implementation solutions including project management, project engineering, configuration, staging, and rollout coordination, and ensuring correct installation and deployment. Configuration services now include development and verification of configuration for intelligent services such as QoS and multicast. For more information about Total Implementation Solutions, visit:

For more information about configuration services for QoS and multicast, contact:

Additional Product Information

Where can I find technical and product specifications and other additional information about the Cisco Catalyst 2940 switches?

For publicly available product literature including data sheets and product specifications, see the Cisco Catalyst 2940 Web site at:

Table Of Contents

Q & A

Cisco Catalyst 2940 Series Switches

Product Overview