Network+ Guide to Networks, 6th Edition
Chapter 6
Network Hardware, Switching, and Routing
At a Glance
Instructor’s Manual Table of Contents

Overview

Objectives

Teaching Tips

Quick Quizzes

Class Discussion Topics

Additional Projects

Additional Resources

Key Terms
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Lecture Notes
Overview
Students need to understand how data arrives at its destination. In data networks, the task of
directing information efficiently to the correct destination is handled by hubs, routers, bridges,
and switches. In this chapter, students will learn about these devices and their roles in managing
data traffic. Material in this chapter relates mostly to functions occurring in the Data Link and
Network layers of the OSI model. Some material also relates to the Physical layer. Students will
learn the concepts involved in moving data from place to place, including issues related to
switching and routing protocols. Students will also see pictures of the hardware - hubs, switches,
bridges, and routers - that make data transfer possible. In addition, students will learn all about
network interface cards, which serve as the workstation’s link to the network and are often the
source of connectivity problems.
Chapter Objectives
After reading this chapter and completing the exercises, the student will be able to:
 Identify the functions of LAN connectivity hardware
 Install, configure, and differentiate between network devices such as, NICs, hubs, bridges,
switches, routers, and gateways
 Explain the advanced features of a switch and understand popular switching techniques,
including VLAN management
 Explain the purposes and properties of routing
 Describe common IPv4 and IPv6 routing protocols
Teaching Tips
NICs (Network Interface Cards)
1. Define and describe NICs (network interface cards).
2. Point out that nearly all NICs contain a data transceiver.
3. Explain why NICs belong to both the Physical layer and Data Link layer of the OSI
model.
4. Describe how advances in NIC technology are making NICs smarter than ever.
5. Emphasize that NICs do not analyze information added by the protocols in Layers 3
through 7 of the OSI model.
6. Explain why it is important to understand NICs.
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Types of NICs
1. Explain what a student should know before ordering or installing a NIC.
2. Describe dependencies of NICs.
3. Explain that NICs vary in the following ways:
a. Access method (for example, Ethernet)
b. Network transmission speed (for example, 100 Mbps versus 1 Gbps)
c. Connector interfaces (for example, RJ-45 versus SC)
d. Number of connector interfaces, or ports
e. Method of interfacing with the computer’s motherboard (for example, on-board,
expansion slot, or peripheral) and interface standard (for example, PCIe or USB)
f. Manufacturer (popular NIC manufacturers include 3Com, Adaptec, D-Link, IBM,
Intel, Kingston, Linksys, Netgear, SMC, and Western Digital, to name just a few)
g. Support for enhanced features, such as PoE, buffering, or traffic management
4. Introduce the Internal Bus Standards category of NICs that are installed on an expansion
board inside a computer.
5. Define and describe the term bus.
6. Define and describe the term expansion slot.
7. Define and describe the term expansion card.
8. Point out that multiple bus types exist.
9. Note that to become part of a computer’s bus, an expansion board must use the same bus
type.
10. Introduce and describe the PCI bus type.
11. Describe the older ISA bus type and compare PCI to ISA.
12. Introduce and describe the PCIe bus type.
13. Describe the advantages of PCIe over PCI.
14. Explain how the PCIe slots differ from PCI slots. Include a discussion on PCIe lanes.
15. Use Figure 6-1 to illustrate a PCIe NIC.
16. Explain how to determine the type of bus a PC uses.
17. Use Figure 6-3 to illustrate a motherboard with multiple expansion slots.
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18. Explain how to determine the best NIC for a PC if the PC motherboard supports more
than one kind of expansion slot.
19. Introduce the Peripheral Bus Standards category of NICs that are installed externally.
a. PCMCIA (Personal Computer Memory Card International Association)
b. USB (universal serial bus)
c. CompactFlash
d. FireWire (IEEE 1394)
20. Explain the Personal Computer Memory Card International Association’s role in setting
standards for peripheral devices.
a. PC Card
b. CardBus
c. ExpressCard
21. Describe the peripheral PCMCIA standard called PC Card.
22. Describe the peripheral PCMCIA standard called CardBus.
23. Describe the peripheral PCMCIA standard called ExpressCard.
24. Introduce and describe the USB peripheral bus standard.
25. Introduce and describe the Firewire peripheral bus standard.
26. Introduce and describe the CompactFlash peripheral bus standard.
27. Introduce and describe the on-board peripheral bus standard.
28. Introduce and describe the wireless peripheral bus standard.
Teaching Students may find more information on how buses work at
http://computer.howstuffworks.com/computer-buses-channel.htm
Tip
Teaching Students may find more information on PCMCIA and Linux at http://pcmciacs.sourceforge.net
Tip
Teaching Students may find more information on PCMCIA/PC Card and CardBus frequently
asked questions at http://www.sycard.com/pcard_qa.html
Tip
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Installing and Configuring NICs
1. Describe the three general steps to install a NIC:
a. Install NIC hardware
b. Install NIC software
c. Configure NIC
2. Explain how to install and configure expansion card NIC hardware.
3. Use Figure 6-4 to illustrate a properly installed NIC.
4. Explain how to install a PCMCIA-standard NIC into a laptop.
5. Explain how to install and configure expansion card NIC software.
6. Define the term device driver.
7. Explain how drivers are installed on purchased computers and computer with new
hardware added.
8. Note that most operating systems come with a multitude of built-in device drivers.
9. Emphasize that if the operating system cannot find a driver for the new hardware, the
driver will have to be installed and configured using NIC software and the operating
system interface.
10. Explain how to install NIC software from a Windows 7 interface.
11. Use Figure 6-5 to illustrate the Windows Network Connection dialog box.
12. Describe how a student may interpret NIC LED indicators to verify NIC functionality
after installation.
13. Define and explain CMOS.
14. Define and explain BIOS.
15. Introduce and explain firmware settings.
16. Explain how to change firmware. Include a discussion on configuration the NIC
configuration utility.
17. Describe how to perform diagnostics with the NIC configuration utility.
a. Define and describe a loopback plug,
b. Describe a loopback test.
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Demonstrate the availability modern Linksys network adapters utilizing various bus
Teaching types by navigating to the Linksys adapter’s product page at
http://homestore.cisco.com/en-us/products/linksys-otherTip
adapters_stcVVcatId552067VVviewcat.htm
Quick Quiz 1
1. True or False: A NIC has no room for a transceiver.
Answer: False
2. A bus is defined by ____.
a. data path speed
b. pin size
c. data path width and clock speed
d. data path width and pin size
Answer: C
3. True or False: One disadvantage to using wireless NICs is that currently they are
somewhat more expensive than wire-bound NICs using the same bus type.
Answer: True
4. ____ is a set of data or instructions that has been saved to a ROM.
Answer: Firmware
5. If the ___ NIC LED indicator light is blinking, this indicates that the NIC is functional
and transmitting frames to the network.
a. ACT
b. LNK
c. TX
d. RX
Answer: C
Modular Interfaces
1. Explain the advantages of using a modular interface for a network interface.
2. Define and describe a GBIC.
3. Define and describe the SFP GBIC.
4. Use Figures 6-7 and 6-8 to illustrate a copper and fiber optic GBIC.
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Repeaters and Hubs
1. Define and describe a repeater.
2. Define and describe a hub.
3. Describe how placement of hubs in a network design can vary.
4. Emphasize that dozens of types of hubs exist and explain how they vary.
5. Point out that hubs have mostly been replaced by switches or routers and explain why.
Demonstrate the availability modern Linksys network routers by navigating to the
Teaching
Linksys router product page at: http://homestore.cisco.com/enTip
us/products/linksys_stcVVcatId551966VVviewcat.htm
Bridges
1. Define and describe bridges.
2. Explain the advantage of using bridges over repeaters and hubs.
3. Explain the disadvantage of using bridges.
4. Explain how a bridge translates data between two segment types.
5. Use Figure 6-10 to illustrate a bridge’s use of a filtering database.
6. Point out that after bridge installation, several methods may be used to learn about the
network and discover the destination address for each packet it handles.
7. Emphasize that bridges are nearly extinct and explain why.
Demonstrate the availability modern Linksys network bridges by navigating to the
Teaching
Linksys bridge product page at: http://homestore.cisco.com/LinksysTip
Powerline_stcVVcatId554690VVviewcat.htm
Switches
1. Define and describe switches.
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2. Emphasize why switches can interpret MAC address information.
3. Note the components within switches.
4. Discuss multiport switches and their advantages over a bridge.
5. Use Figure 6-11 to illustrate switches.
6. Discuss how switches have been used historically.
7. Describe the disadvantages of switches, noting that some network administrators have
replaced backbone routers with switches.
Switch Installation
1. Explain the best way to ensure that a switch is installed properly.
2. Review the general steps for installing a switch.
3. Use Figure 6-12 to illustrate how to connect a workstation to a switch.
4. Use Figure 6-13 to illustrate a switch on a small network.
Switching Methods
1. Introduce switching methods.
2. Define and describe the cut-through mode switching method.
3. Describe the advantages and disadvantages of the cut-through method, as well as where it
is best implemented.
4. Define and describe the store-and-forward mode switching method.
5. Describe the advantages and disadvantages of the store-and-forward mode, as well as
where it is best implemented.
Demonstrate the availability modern Linksys network switches by navigating to the
Teaching
Linksys bridge product page at: http://homestore.cisco.com/en-us/products/linksysTip
other-routers_stcVVcatId552066VVviewcat.htm
Teaching Students may find more information on how switches work at:
http://computer.howstuffworks.com/lan-switch.htm
Tip
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VLANs and Trunking
1. Define a VLAN (virtual local area networks).
2. Define the term broadcast domain.
3. Define the term collision domain and contrast it with a broadcast domain.
4. Use Figure 6-14 to illustrate a simple VLAN design.
5. Describe the advantages and reasons for using a VLAN.
6. Explain how to create and maintain a VLAN.
7. Emphasize the critical step in creating the VLAN.
8. Use Figure 6-15 to illustrate the result of the show vlans command on a Cisco switch.
9. Discuss potential useful situation for VLANs.
10. Define the term trunking.
11. Define the term trunk.
12. Explain the advantages of VLAN trunking.
13. Note considerations in VLAN configuration planning.
Students may find more information on Understanding VLAN Trunk Protocol
Teaching (VTP) from Cisco at:
http://www.cisco.com/en/US/tech/tk389/tk689/technologies_tech_note09186a0080
Tip
094c52.shtml
STP (Spanning Tree Protocol)
1. Introduce and define STP (Spanning Tree Protocol).
2. Use Figure 6-17 to illustrate an enterprise-wide switched network requiring STP.
3. Review the three steps STP performs.
4. Use Figure 6-18 to illustrate STP-selected paths on a switched network.
5. Review the history of STP.
6. Discuss the newer protocol as well as the proprietary protocols.
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7. Emphasize that when installing switches on your network, you do not need to enable or
configure STP (or the more current version that came with your switch).
Content and Multilayer Switches
1. Define a Layer 3 switch.
2. Define a Layer 4 switch.
3. Define a content switch.
4. Describe the advantages and disadvantages of these types of switches.
5. Note that distinguishing factors between Layer 3 and Layer 4 switches are manufacturer
dependent.
6. Discuss higher layer switches and their use.
Routers
1. Define and describe a router.
Router Characteristics and Functions
1. Explain the strength of routers.
2. Emphasize that routers are indispensible in large WAN and LANs like the Internet.
3. Describe the components in a router.
4. Define and describe a modular router.
5. Note the use of inexpensive routers in the home and small office.
6. Use Figure 6-19 to illustrate three routers.
7. Describe the tasks performed by routers.
8. Describe the optional functions a router may contain.
9. Describe the two methods of directing network traffic:
a. Static routing
b. Dynamic routing
10. Describe the installation characteristics of small networks and large networks.
11. Use Figure 6-20 to illustrate the placement of routers on a LAN.
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Routing Protocols
1. Define and describe the term best path.
2. Describe a routing protocol.
3. Define and describe router convergence time.
4. Introduce distance-vector routing protocols.
5. Explain how the RIP (Routing Information Protocol) works.
6. Explain how RIPv2 (Routing Information Protocol version 2) works.
7. Explain how BGP (Border Gateway Protocol) works.
8. Introduce link-state routing protocols.
9. Explain how OSPF (Open Shortest Path First) works.
10. Explain how IS-IS (Intermediate System to Intermediate System) works.
11. Introduce the concept of hybrid routing protocols.
12. Explain how the EIGRP (Enhanced Interior Gateway Routing Protocol) works.
Gateways and Other Multifunction Devices
1. Define and describe gateways.
2. Discuss popular gateways.
Teaching
Tip
Students may find more information on gateway protocols at:
http://www.cisco.com/en/US/tech/tk1077/tsd_technology_support_protocol_home.
html
Quick Quiz 2
1. True or False: Repeaters operate in the Physical layer of the OSI model.
Answer: True
2. True or False: Bridges are protocol independent.
Answer: True
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3. Switches that operate anywhere between Layer 4 and Layer 7 are also known as ____or
application switches.
Answer: content switches
4. ____ is a technique in which a network administrator programs a router to use specific
paths between nodes.
Answer: Static routing
5. A gateway must operate at ____ of the OSI model.
a. multiple layers
b. Layer 2
c. Layer 3
d. Layers 4-7
Answer: A
Class Discussion Topics
1. Wireless technology is widely deployed in the modern network. Have students discuss
some of the most recent changes or developments in the wireless networking field and the
impact of those changes on the network overall. For example, is it necessary to
potentially reengineer parts of the network to support a migration to more wireless or
wire-free type of network?
2. Many students will most likely have a small home network or know someone who does.
Have student describe the communications devices in these networks. Are they wireless
or wired? Are there routers, switches, or hubs? Describe experiences, good and bad, with
these networks.
Additional Projects
1. Have each student research available routers. The report should include a write-up for
three to five devices. Included in the write-up should be a description of the device,
including the manufacturer, the model, the seller, the cost, and a summary of the
manufacturer specifications.
2. Have students research the EIGRP routing protocol in more depth. The student should
provide a report, including sections on: Introduction, Background and History, Technical
Specifications, Implementation, Barriers, and Summary.
Additional Resources
1. PCMCIA Official Web site
http://www.pcmcia.org/
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2. PCI Special Interest Group
http://www.pcisig.com/home
3. USB (Universal Serial Bus) Implementer's Forum
http://www.usb.org/home
4. CompactFlash Association
http://www.compactflash.org
5. CiscoPress Sample Chapter on VLANs and Trunking
http://www.ciscopress.com/articles/article.asp?p=29803
6. Cisco router information
http://www.cisco.com/en/US/products/hw/routers/index.html
Key Terms
 802.1D The IEEE standard that describes, among other things, bridging and STP
(Spanning Tree Protocol).
 802.1q The IEEE standard that specifies how VLAN and trunking information appear in
frames and how switches and bridges interpret that information.
 802.1w The IEEE standard that describes RSTP (Rapid Spanning Tree Protocol), which
evolved from STP (Spanning Tree Protocol).
 access port The interface on a switch used for an end node. Devices connected to access
ports are unaware of VLAN information.
 application switch A switch that provides functions between Layer 4 and Layer 7 of the
OSI model.
 backplane A synonym for motherboard, often used in the context of switches and
routers.
 best path The most efficient route from one node on a network to another. Under optimal
network conditions, the best path is the most direct path between two points. However,
when traffic congestion, segment failures, and other factors create obstacles, the most
direct path might not be the best path.
 BGP (Border Gateway Protocol) A distance-vector routing protocol capable of
considering many factors in its routing metrics. BGP, an Exterior Gateway Protocol, is
the routing protocol used on Internet backbones.
 BID (Bridge ID) A combination of a 2-byte priority field and a bridge’s MAC address,
used in STP (Spanning Tree Protocol) to select a root bridge.
 Border Gateway Protocol See BGP.
 border router A router that connects an autonomous LAN with an exterior network—for
example, the router that connects a business to its ISP.
 bridge A connectivity device that operates at the Data Link layer (Layer 2) of the OSI
model and reads header information to forward packets according to their MAC
addresses. Bridges use a filtering database to determine which packets to discard and
which to forward. Bridges contain one input and one output port and separate network
segments.
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 Bridge ID See BID.
 bus The type of circuit used by a computer’s motherboard to transmit data to
components. Most new Pentium computers use buses capable of exchanging 32 or 64 bits
of data. As the number of bits of data a bus handles increases, so too does the speed of
the device attached to the bus.
 content switch A switch that provides functions between Layer 4 and Layer 7 of the OSI
model.
 convergence time The time it takes for a router to recognize a best path in the event of a
change or network outage.
 cost In the context of routing metrics, the value assigned to a particular route as judged
by the network administrator. The more desirable the path, the lower its cost.
 cut-through mode A switching mode in which a switch reads a frame’s header and
decides where to forward the data before it receives the entire packet. Cut-through mode
is faster, but less accurate, than the other switching method, store-and-forward mode.
 device driver The software that enables an attached device to communicate with the
computer’s operating system.
 distance-vector The simplest type of routing protocols, these determine the best route for
data based on the distance to a destination. Some distance-vector routing protocols, like
RIP, only factor in the number of hops to the destination, while others take into account
latency and other network traffic characteristics.
 driver See device driver.
 dynamic routing A method of routing that automatically calculates the best path
between two nodes and accumulates this information in a routing table. If congestion or
failures affect the network, a router using dynamic routing can detect the problems and
reroute data through a different path. Modern networks primarily use dynamic routing.
 EGP (Exterior Gateway Protocol) A routing protocol that can span multiple,
autonomous networks. BGP and EIGRP are examples of Exterior Gateway Protocols.
 EIGRP (Enhanced Interior Gateway Routing Protocol) A routing protocol developed
in the mid-1980s by Cisco Systems that has a fast convergence time and a low network
overhead, but is easier to configure and less CPU-intensive than OSPF. EIGRP also
offers the benefits of supporting multiple protocols and limiting unnecessary network
traffic between routers.
 Enhanced Interior Gateway Routing Protocol See EIGRP.
 ethtool A popular tool for viewing and modifying network interface properties on Linux
computers.
 expansion board A circuit board used to connect a device to a computer’s motherboard.
 expansion card See expansion board.
 expansion slot A receptacle on a computer’s motherboard that contains multiple
electrical contacts into which an expansion board can be inserted.
 Exterior Gateway Protocol See EGP.
 exterior router A router that directs data between nodes outside a given autonomous
LAN, for example, routers used on the Internet’s backbone.
 filtering database A collection of data created and used by a bridge that correlates the
MAC addresses of connected workstations with their locations. A filtering database is
also known as a forwarding table.
 firewall A device (either a router or a computer running special software) that selectively
filters or blocks traffic between networks. Firewalls are commonly used to improve data
security.
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 forwarding table See filtering database.
 gateway A combination of networking hardware and software that connects two
dissimilar kinds of networks. Gateways perform connectivity, session management, and
data translation, so they must operate at multiple layers of the OSI model.
 gateway router See border router.
 GBIC (Gigabit interface converter) A standard type of modular interface designed in
the 1990s for Gigabit Ethernet connections. GBICs may contain RJ-45 or fiber-optic
cable ports (such as LC, SC, or ST). They are inserted into a socket on a connectivity
device’s backplane.
 Gigabit interface converter See GBIC.
 hot-swappable The feature of a component that allows it to be installed or removed
without disrupting operations.
 hub A connectivity device that retransmits incoming data signals to its multiple ports.
Typically, hubs contain one uplink port, which is used to connect to a network’s
backbone.
 IGP (Interior Gateway Protocol) A routing protocol, such as RIP, that can only route
data within an autonomous (internal) network.
 interior router A router that directs data between nodes on an autonomous LAN.
 Intermediate System to Intermediate System See IS-IS.
 Interior Gateway Protocol See IGP.
 IS-IS (Intermediate System to Intermediate System) A link-state routing protocol that
uses a best-path algorithm similar to OSPF’s. IS-IS was originally codified by ISO,
which referred to routers as “intermediate systems,” thus the protocol’s name. Unlike
OSPF, IS-IS is designed for use on interior routers only.
 Layer 3 switch A switch capable of interpreting data at Layer 3 (Network layer) of the
OSI model.
 Layer 4 switch A switch capable of interpreting data at Layer 4 (Transport layer) of the
OSI model.
 link-state A type of routing protocol that enables routers across a network to share
information, after which each router can independently map the network and determine
the best path between itself and a packet’s destination node.
 loopback adapter See loopback plug.
 loopback plug A connector used for troubleshooting that plugs into a port (for example,
a serial, parallel, or RJ-45 port) and crosses over the transmit line to the receive line,
allowing outgoing signals to be redirected back into the computer for testing.
 main bus See bus.
 mini GBIC See SFP.
 on-board NIC A NIC that is integrated into a computer’s motherboard, rather than
connected via an expansion slot or peripheral bus.
 on-board port A port that is integrated into a computer’s motherboard.
 Open Shortest Path First See OSPF.
 OSPF (Open Shortest Path First) A routing protocol that makes up for some of the
limitations of RIP and can coexist with RIP on a network.
 PCIe (PCI Component Interconnect Express) A 32-bit bus standard capable of
transferring data at up to 1 Gbps per data path, or lane, in full-duplex transmission. PCIe
is commonly used for expansion board NICs.
 PCI Component Interconnect Express See PCIe.
 Rapid Spanning Tree Protocol See RSTP.
Network+ Guide to Networks, 6th Edition
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 RIP (Routing Information Protocol) The oldest routing protocol that is still widely
used, RIP is a distance-vector protocol that uses hop count as its routing metric and
allows up to only 15 hops. It is considered an IGP. Compared with other, more modern,
routing protocols, RIP is slower and less secure.
 RIPv2 (Routing Information Protocol version 2) An updated version of the original
RIP routing protocol, which makes up for some of its predecessor’s overhead and
security flaws. However, RIPv2’s packet forwarding is still limited to a maximum 15
hops.
 root bridge The single bridge on a network selected by the Spanning Tree Protocol to
provide the basis for all subsequent path calculations.
 router A multiport device that operates at Layer 3 of the OSI model and uses logical
addressing information to direct data between networks or segments. Routers can connect
dissimilar LANs and WANs running at different transmission speeds and using a variety
of Network layer protocols. They determine the best path between nodes based on traffic
congestion, available versus unavailable routes, load balancing targets, and other factors.
 Routing Information Protocol See RIP.
 Routing Information Protocol version 2 See RIPv2.
 routing metric The method used by routing protocols to determine the best path for data
to follow over a network. Routing metrics may be calculated using any of several
variables, including number of hops, bandwidth, delay, MTU, cost, and load.
 routing protocols The means by which routers communicate with each other about
network status. Routing protocols determine the best path for data to take between nodes.
 routing switch See Layer 3 switch.
 routing table A database stored in a router’s memory that maintains information about
the location of hosts and best paths for forwarding packets to them.
 RSTP (Rapid Spanning Tree Protocol) As described in IEEE’s 802.1w standard, a
version of the Spanning Tree Protocol that can detect and correct for network changes
much more quickly.
 runt An erroneously shortened packet.
 SFP (small form-factor pluggable) transceiver A standard hot-swappable network
interface used to link a connectivity device’s backplane with fiber-optic or copper
cabling. SFPs are known as mini GBICs because they perform a similar function as
GBICs, but have a smaller profile. Current SFP standards enable them to send and
receive data at up to 10 Gbps.
 SFP GBIC See SFP.
 Spanning Tree Protocol See STP.
 static routing A technique in which a network administrator programs a router to use
specific paths between nodes. Because it does not account for occasional network
congestion, failed connections, or device moves and requires manual configuration, static
routing is not optimal.
 store-and-forward mode A method of switching in which a switch reads the entire data
frame into its memory and checks it for accuracy before transmitting it. Although this
method is more time consuming than the cut-through method, it allows store-and-forward
switches to transmit data more accurately.
 STP (Spanning Tree Protocol) A switching protocol defined in IEEE 802.1D. STP
operates in the Data Link layer to prevent traffic loops by calculating paths that avoid
potential loops and by artificially blocking links that would complete a loop. Given
changes to a network’s links or devices, STP recalculates its paths.
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 switch A connectivity device that logically subdivides a network into smaller, individual
collision domains. A switch operates at the Data Link layer of the OSI model and can
interpret MAC address information to determine whether to filter (discard) or forward
packets it receives.
 system bus See bus.
 trunk port The interface on a switch capable of managing traffic from multiple VLANs.
 trunking The aggregation of multiple logical connections in one physical connection
between connectivity devices. In the case of VLANs, a trunk allows two switches to
manage and exchange data between multiple VLANs.
 uplink port A port on a connectivity device, such as a hub or switch, used to connect it
to another connectivity device.
 virtual local area network See VLAN.
 VLAN (virtual local area network) A network within a network that is logically
defined by grouping its devices’ switch ports in the same broadcast domain. A VLAN
can consist of any type of network node in any geographic location and can incorporate
nodes connected to different switches.
 VLAN trunking protocol See VTP.
 VTP (VLAN trunking protocol) Cisco’s protocol for exchanging VLAN information
over trunks. VTP allows one switch on a network to centrally manage all VLANs.