Lesson 3- Installing and Configuring Switched Networks

BPDU

(Bridge Protocol Data Unit) The frames package exchanged by switches to prevent switching loops.

intranet

A private network that is only accessible by the organization's own personnel.

modular switch

switch that uses plug-in cards to configure the switch with different numbers and types of ports.

MAC address table

(Media Access Control address table) On a switch, the table that keeps track of the MAC addresses associated with each port. As the switch uses a type of memory called Content Addressable Memory (CAM), this is sometimes called the CAM table.

Analog Signal

A signal that carries information as continuous waves of electromagnetic or optical energy.

hybrid topology

Any topology that exhibits the characteristics of more than one standard network topology.

Under STP, if a host port is working as normal, what state is it in?

Forwarding

STP

(Spanning Tree Protocol) A switching protocol that prevents network loops by dynamically disabling links as needed.

SPAN

(Switched Port Analyzer) The CISCO implementation of port mirroring.

CAN

(campus area network) A LAN that spreads over several buildings within the same overall area.

PSE

(power sourcing equipment) Devices that provide power over an Ethernet cable to devices connected to the Ethernet cable.

SOHO network

(small office home office) A small network that provides connectivity and resource sharing for a small office or home office.

bridge

A device that joins two network segments at the Data Link layer. Each bridge port is a separate collision domain, but the segments joined to each bridge port are in a single broadcast domain.

tap

A device used to eavesdrop on communications at the Physical layer. An Ethernet tap can be inserted between a switch and a node, while a passive tap can intercept emanations from unshielded cable.

repeater

A layer 1 device that takes a signal and repeats it to the devices that are connected to it. Repeaters can be used to maintain signal integrity and amplitude to overcome distance limitations imposed by a particular media type.

port mirroring

A monitoring technique in which one port on a switch is configured to send a copy of all its traffic to a second port.

SAN

A network dedicated to data storage, typically consisting of storage devices and servers connected to switches via host bus adapters.

Star Topology

A network design in which each node is connected to a central point, typically a switch or a router. The central point mediates communications between the attached nodes.

Bus Topology

A network layout in which there is one main trunk, or backbone, that all the various computers and network devices are connected to.

PAN

A network that connects two to three devices with cables and is most often seen in small or home offices.

WAN

A network that spans multiple geographic locations.

physical ring topology

A network topology in which all network nodes are connected in a circle.

logical bus topology

A network topology in which all nodes receive the data transmission at the same time, regardless of the physical wiring layout of the network.

WLAN

A network using wireless radio communications based on some variant of the 802.11 standard series.

switch

A networking device that receives incoming data, reviews the destination MAC address against an internal address table, and sends the data out through the port that contains the destination MAC address.

hub

A networking device working at the Physical layer that is used to connect the drops in a physical star topology network into a logical bus topology. Also called a multiport repeater.

switching loop

A problem that occurs when two Layer 2 switches are connected over redundant paths with either two switches being connected using two different links or a ring of switches connected to each other. This causes flooded frames to circulate the network perpetually.

hotspot

A public, open WLAN.

SDN

A software application for defining policy decision on the control plane.

fixed switch

A switch that comes with a set number of ports that cannot be changed or upgraded.

managed switch

A switch that enables you to monitor and configure its operation. Also called an intelligent switch.

failover

A technique that ensures a redundant component, device, or application can quickly and efficiently take over the functionality of an asset that has failed.

Mesh Topology

A topology often used in WANs where each device has (in theory) a point-to-point connection with every other device (fully connected); in practice, only the more important devices are directly interconnected (partial mesh).

P2P connection

A topology that provides a one-to-one connection between two nodes.

crossover cable

A twisted pair cable wired as T568A on one end and as T568B on the other end.

LAN

A type of network covering various sizes but generally considered to be restricted to a single geographic location and owned/managed by a single organization.

What four layers can be used to conceptualize distributed switching hierarchy?

Access, distribution, core, and data center.

What is microsegmentation?

Each switch port creates a separate collision domain for each attached host, essentially eliminating the effect of collisions on network performance and allowing each host exclusive use of the full media bandwidth.

What is happening if a switch is flooding?

It is sending frames out on all ports (other than the source port). This typically happens when it is learning MAC addresses or forwarding broadcast traffic.

How does a switch keep track of the hardware addresses of hosts connected to its ports?

It uses a MAC address table stored in content addressable memory (CAM).

PoE

Power over Ethernet

What is the function of STP?

Spanning Tree Protocol (STP) prevents switching loops. A switching loop is where flooded traffic is continually looped around a network with redundant links between switches.

designated port

Switch ports that can forward traffic down through the network with the least cost.

stackable switch

Switches that can be connected together and operate as a group, and managed as a single unit.

broadcast storm

The flooding of a network with frames caused by a switching loop.

Microsegmentation

The means by which an Ethernet switch establishes per-port collision domains, allowing full duplex communication and eliminating the effect of contention across all of the switch ports.

Ring Topology

Topology where the computers are connected on a loop or ring. Data flows in one direction only.

distributed switching

multiple switch appliances arranged in a fault tolerant hierarchy, and often centrally managed and automated using Software Defined Networking (SDN).

extranet

private network that provides some access to outside parties, particularly vendors, partners, and select customers.