Switch
- 1. SWITCH
- 2. WHAT IS A SWITCH? • A network switch also called switching hub, is a networking hardware that connects devices on a computer network by using packet switching to receive and forward data to the destination device.
- 3. WHAT IS THE RESPONSIBILITY OF THE SWITCH TO THE LOCAL AREA NETWORK? • It provides connection point for end users into the enterprise network and are also primarily responsible for the control of information within the LAN environment • It uses MAC addresses to forward data at the data link layer (layer 2) of the OSI model
- 4. TYPE OF NETWORK SWITCH There are two main categories of switches: modular and fixed configuration • Modular Switches • Fixed-configuration switches a) Unmanaged switches b) Managed switches c) Smart switches
- 5. MODULAR SWITCH • Modular switches let you add expansion modules as needed, giving you flexibility as network requirements change. Expansion modules are application-specific and include those for firewalls, wireless connectivity, or network analysis. They may also allow for additional interfaces, power supplies, or cooling fans. This type of switch provides you with the most flexibility, but at a higher cost
- 6. FIXED-CONFIGURATION SWITCHES • Unmanaged switches Unmanaged switches are typically used to provide basic connectivity. They're designed to be plug and play; no configuration is needed. Unmanaged switches are most effective when only basic switching and connectivity are required. You will often see them in home networks or wherever only a few ports are needed, such as at a desk, in a lab, or in a conference room
- 7. FIXED-CONFIGURATION SWITCHES • Smart switches • Smart switches offer some management and segmentation, quality of service, and security capabilities, so they can be a cost-effective alternative to modular switches. Still, they are not as scalable as managed switches. These switches are typically deployed at the edge of a large network (while managed switches are used in the core), as the infrastructure for smaller networks, or for low complexity networks
- 8. FIXED-CONFIGURATION SWITCHES • Managed switches • Among fixed-configuration switches, managed switches are designed to deliver the most comprehensive set of features to provide the best application experience, the highest levels of security, the most precise control and management of the network, and the greatest scalability. As a result, managed switches are usually deployed as aggregation/access switches in very large networks or as core switches in smaller networks. • Managed switches are the most expensive option of fixed-configuration switches and are most common in organizations with large- or growing- networks
- 9. FOUR SWITCH OPTIONS TO KEEP IN MIND In addition to evaluating switch categories, you should also consider network switch speeds, number of ports, power-over- Ethernet features, and stacking capabilities. • Switch speeds • Switches are available in different throughputs or speeds, the rate they transmit data in megabits per second (Mbps). For example, fixed-configuration switches can provide Fast Ethernet (10/100 Mbps), Gigabit Ethernet (10/100/1000 Mbps), Ten Gigabit (10/100/1000/10000 Mbps), and even 40/100 Gbps (gigabits per second) speeds. The switch speed you choose depends on the type of throughput you need. If, for example, you need to move large data files on a regular basis, you should consider a Gigabit Ethernet switch. • Number of ports • As is the case with switch speed, the number of ports available in a switch can vary. The bigger your small business and the more network users you have, the more ports you'll need. Fixed-configuration switches are usually available with five, eight, 10, 16, 24, 28, 48, or 52 ports. • Power over Ethernet (PoE) vs. non-PoE • PoE lets you power a device—such as an IP phone, surveillance camera, or wireless access point—over the cable that is used for data traffic. This allows you to place endpoints anywhere, even in those areas that are usually difficult to reach. Switches with PoE are more expensive, however. As you evaluate your options, think about the devices you would like to connect to determine whether PoE is required. • Stackable vs. standalone switches • As your business (and your network) grows, you will likely need to support more and more devices, which will mean investing in more switches. Just as its name implies, a standalone switch is managed and configured as an individual entity with limited capacity. If there is a problem, troubleshooting is also switch specific. • In contrast, stackable switches can be connected to increase the capacity and availability of your network. Rather than configuring, managing, and troubleshooting each switch, you can treat the "stack" as a single unit. This means that if any part of the stack fails, the stack will route around the failure, so your network keeps running
- 10. HOW DOES A SWITCH WORK? • A network switch is a device that connects devices together on a LAN. A switch is essentially a multiport network bridge and performs the same basic functions as a bridge, but at much faster speeds and with many additional features. Each port on a switch is in a separate collision domain and can run in the full duplex mode, which means that hosts connected to a switch port can transmit to the switch at the same time that the switch transmits to them. • An Ethernet switch usually works at the Data link layer of the OSI model (Layer 2). It manages the flow of data across a network by inspecting the incoming frame’s destination MAC address and forwarding the frame only to the host for which the message was intended. Each switch has a dynamic table (called the MAC address table) that maps MAC addresses to ports. With this information, a switch can identify which system is sitting on which port and where to Host A is trying to communicate with Host C and sends a packet with the Host C’s destination MAC address. The packet arrives at the switch, which looks at the destination MAC address. The switch then searches that MAC address in its MAC address table. If the MAC address is found, the switch then forwards the packet only out the port connected to the frame’s destination. Hosts connected to other ports will not receive the frame.