Network Devices - CompTIA A+ 220-1101 - 2.2

New Section

This section provides an introduction to the different types of systems used for network communication in data centers and explains the purpose and usage of routers, switches, and access points.

Types of Network Communication Devices

• Routers are devices that forward traffic between different IP subnets. They operate at layer 3 of the OSI model and are commonly referred to as layer 3 devices. Routers can connect IP subnets with the same or different topologies.

• Switches are devices used for connecting computers or devices within a local network. They determine where traffic should be forwarded based on the destination MAC address within a packet. Switches can have multiple interfaces and often support Power over Ethernet (PoE).

• Layer 3 switches, also known as multilayer switches, combine routing functionality with switching capabilities.

• Access points provide wireless connectivity for local networks by bridging the wired and wireless connections. They make forwarding decisions based on destination MAC addresses.

New Section

This section focuses on understanding routers and their role in forwarding traffic between IP subnets.

Understanding Routers

• Routers forward traffic between different IP subnets using the IP address within packets.

• Routing takes place at layer 3 of the OSI model, making routers layer 3 devices.

• Some routers can be configured inside a switch, resulting in layer 3 switches that combine routing and switching functionalities.

New Section

This section discusses how routers can connect networks with different topologies and interfaces.

Connecting Different Networks with Routers

• Routers are commonly used to connect networks with different topologies together.

• A router's interfaces can connect LAN, WAN, copper, and fiber connections in a single device.

New Section

This section explains the role of switches in network communication and their ability to forward traffic based on MAC addresses.

Understanding Switches

• Switches are commonly used for connecting devices within a local network.

• They determine where traffic should be forwarded based on the destination MAC address within packets.

• Switches can forward traffic at high speeds due to hardware-based forwarding decisions.

• Many switches have Application Specific Integrated Circuits (ASICs) that enable fast throughput.

• Some switches in enterprise networks have numerous interfaces and support Power over Ethernet (PoE).

• Layer 3 switches or multilayer switches have additional routing functionality.

New Section

This section compares unmanaged switches with managed switches and highlights their differences in terms of configuration options.

Unmanaged Switches vs. Managed Switches

• Unmanaged switches provide simple connectivity without many configuration options.

• Devices connected to an unmanaged switch are typically on the same VLAN, as VLAN configuration is not possible.

• Unmanaged switches lack integration with other protocols or devices, such as SNMP for performance monitoring.

• Managed switches offer additional capabilities and configuration options for network administrators.

• Managed switches allow configuring different interfaces on separate IP subnets or VLANs.

• They may also prioritize specific types of traffic, such as Voice over IP (VoIP).

New Section

This section explores advanced features available in managed switches, including Spanning Tree Protocol (STP) and port mirroring.

Advanced Features of Managed Switches

• Spanning Tree Protocol (STP) helps prevent loops between multiple interconnected switches.

• Port mirroring allows copying traffic from one port to another for troubleshooting or packet analysis using a protocol analyzer.

• These features are typically available only in managed switches, not unmanaged ones.

New Section

This section discusses the purpose and functionality of access points in providing wireless connectivity.

Understanding Access Points

• Access points bridge the wired and wireless connections, extending the local network's reach.

• They do not perform routing between subnets or network address translation (NAT).

• Access points make forwarding decisions based on destination MAC addresses, similar to switches.

Conclusion

This markdown file provides a comprehensive summary of the given transcript, covering topics such as routers, switches, and access points. The information is organized into sections with clear headings and bullet points for easy reference. Timestamps are included where available to help users study the transcript more effectively.

New Section

This section discusses the concept of patch panels and their role in connecting devices in a network.

Patch Panels and Wiring Closets

• A patch panel is used to connect devices from desks to a central wiring closet.

• The cables from each desk are connected to the patch panel, creating permanent runs.

• RJ45 connectors on the other side of the patch panel extend the connections to interfaces on switches.

• Patch panels allow for easy movement of connections between switches without having to move cables inside the wiring closet.

New Section

This section explains how patch panels facilitate easy movement of connections between switches.

Moving Connections with Patch Panels

• When someone needs to be moved from one switch connection to another, it can be done easily with a patch panel.

• Instead of moving cables inside the wiring closet, you simply disconnect from one switch and connect that port on the patch panel to a different switch.

• This process involves using shorter labeled cables, making it quick and efficient.

New Section

This section provides further details about patch panels and their configuration.

Understanding Patch Panel Connections

• Behind a patch panel, there are cable runs coming from desks, while RJ45 connectors on the front connect to switches.

• The wiring between user workstations and the closet remains unchanged as it is permanently connected at the back of the patch panel.

• Making changes only requires moving cables on the front of the patch panel, minimizing potential problems during changes.

New Section

This section discusses different types of firewalls based on their capabilities.

Firewalls: Layer 4 and Layer 7 Devices

• Traditional firewalls operate at layer 4 (OSI model) and control traffic based on IP addresses and port numbers.

• Some firewalls can understand application layer traffic, making them layer 7 devices.

• Firewalls can also act as endpoints for encrypted tunnels or proxies, enhancing security and control over network traffic.

New Section

This section explains Power over Ethernet (PoE) and its applications.

Power Over Ethernet (PoE)

• PoE allows devices to be powered through the ethernet cable used for data transfer.

• It is commonly used with access points, cameras, and other devices where running power separately may be challenging.

• PoE can be provided directly from a switch (endspan) or through an injector (midspan) if the switch does not support PoE.

New Section

This section discusses different types of switches that support PoE and their identification.

Identifying PoE Support on Switches

• Most switches indicate which interfaces support PoE. They are often marked with a blue line across the top.

• IEEE 802.3af is the original standard for PoE, but there are different standards depending on the switch type.

• Different devices require different types of power, so it's important to ensure compatibility between the device and the switch's PoE standard.

Power over Ethernet (POE++) Standards

This section discusses the POE++ standards, specifically the IEEE 802.3bt standard. It explains the power and current specifications for Type 3 and Type 4 POE++, which are designed to work with 10 gigabit per second ethernet.

POE++ Standards

• The POE++ standard, also known as IEEE 802.3bt, provides power over ethernet.

• Type 3 POE++ delivers 51 watts with a maximum current of 600 milliamps.

• Type 4 POE++ delivers 71.3 watts with a maximum current of 960 milliamps.

• These standards were designed to support high-power devices and work with 10 gigabit per second ethernet.

Hubs vs Switches in Networking

This section compares hubs and switches in networking, highlighting their differences in terms of functionality and efficiency.

Hubs

• Hubs were commonly used before switches to connect devices on a network.

• Hubs are often referred to as multi-port repeaters because they copy and send data received on one interface to all other interfaces.

• This broadcasting method is inefficient for communication and does not support full duplex communication.

• Devices connected to a hub operate at half duplex, leading to slower performance as more devices are added.

Switches

• Switches are more intelligent devices compared to hubs.

• They provide better performance by selectively forwarding data only to the intended recipient device.

• Switch-based networks allow for full duplex communication, improving efficiency and speed.

Limitations of Hubs in Network Performance

This section discusses the limitations of hubs in terms of network performance as more devices are added.

Performance Impact

• As more devices are connected to a hub, the performance of the network tends to slow down.

• Since all data is re-transmitted to every interface on the hub, the device becomes overloaded with increased load and devices.

• This inefficiency in communication leads to slower performance and decreased network speed.

Outdated Nature of Hubs

This section highlights that hubs are outdated for modern networks and are only available in lower speeds on secondary or used markets.

Outdated Technology

• Hubs are considered outdated for modern networks.

• They are typically available in 10 megabit and 100 megabit speeds.

• Finding new hubs is rare, as they are mostly found in secondary or used markets.

Cable Modems for Broadband Communication

This section explains cable modems used for broadband communication, which support multiple frequencies of traffic over a single wire.

Cable Modems

• Cable modems allow communication over broadband connections using cable television infrastructure.

• They support multiple frequencies of traffic over a single wire, enabling services like video signals for television, phone lines, and internet data.

• The standard for sending data over cable networks is called DOCSIS (Data Over Cable Service Interface Specification).

• Cable modems can support higher speeds up to one gigabit per second, depending on the service provider.

Services and Connectivity Options with Cable Modems

This section discusses the different services and connectivity options available with cable modems.

Multiple Services

• Cable networks offer multiple services such as internet data, video signals for television, and analog telephone connections.

• The total speeds available depend on the service provider's offerings.

Connectivity Options

• Cable modems provide connections for both internet data and analog telephone lines.

• Users can choose to connect either to the internet or use analog telephone services.

DSL Modems for Internet Connectivity

This section explains DSL modems used for internet connectivity through traditional telephone lines.

DSL Modems

• DSL modems, specifically ADSL (Asymmetric Digital Subscriber Line) modems, are used to connect to the internet via traditional telephone lines.

• DSL is asymmetric, with faster download speeds compared to upload speeds.

• There is a distance limitation for DSL connections, typically around 10,000 feet from the Central Office (CO).

• Speeds for DSL range from 52 megabit down and 16 megabit up, but faster implementations depend on the provider's capabilities.

Limitations and Distance Considerations of DSL

This section discusses limitations and distance considerations associated with DSL connections.

Limitations of DSL

• The signal strength weakens over distance in a DSL connection.

• Beyond a certain distance from the Central Office (CO), data reception becomes unreliable or impossible.

Distance Considerations

• The maximum distance limit for reliable DSL connection is usually around 10,000 feet from the CO.

• Users closer to the CO tend to experience faster throughput compared to those farther away.

Fiber Optic Networks and ONTs

This section introduces fiber optic networks and Optical Network Terminals (ONTs) used for connecting homes or premises to ISP fiber networks.

Fiber Optic Networks

• Fiber optic networks use optical fibers to transmit data signals at high speeds.

• To connect to a fiber network, an ONT (Optical Network Terminal) is required.

• The ONT is usually located outside the building and converts the fiber network signals into usable copper ethernet signals for internal use.

ONT and Demarcation Point

• The ONT serves as a demarcation point between the ISP's network and the user's internal network.

• It is typically located on the outside of a building, separating responsibilities between the user and service provider.

• The demarcation point determines which wiring is the responsibility of each party.

Location of Demarcation Point

This section discusses the location of the demarcation point in relation to data centers or homes.

Demarcation Point Location

• The demarcation point can be located within a data center or on the outside of a home.

• Its purpose is to clearly define responsibilities for wiring maintenance and troubleshooting.

• Wiring inside a house up to the demarcation point is the user's responsibility, while anything beyond that falls under the service provider's responsibility.

Network Interface Cards (NICs)

This section explains Network Interface Cards (NICs) used for wired ethernet connections in various devices.

NICs in Devices

• All devices connecting to wired ethernet networks have Network Interface Cards (NICs).

• NICs provide connectivity by plugging into servers, laptops, desktop computers, or other devices with an ethernet interface.

• Different types of NICs exist for various topologies such as wide area network serial connections or wireless interfaces.