![Page 1: Chapter 17 Connecting Devices And Virtual LANs Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display](https://reader033.vdocument.in/reader033/viewer/2022061522/56649f3c5503460f94c5ac9f/html5/thumbnails/1.jpg)
Chapter 17
Connecting Devices
AndVirtualLANs
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
![Page 2: Chapter 17 Connecting Devices And Virtual LANs Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display](https://reader033.vdocument.in/reader033/viewer/2022061522/56649f3c5503460f94c5ac9f/html5/thumbnails/2.jpg)
Chapter 17: Outline
17.1 17.1 CONNECTING DEVICESCONNECTING DEVICES
17.2 17.2 VIRTUAL LANSVIRTUAL LANS
![Page 3: Chapter 17 Connecting Devices And Virtual LANs Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display](https://reader033.vdocument.in/reader033/viewer/2022061522/56649f3c5503460f94c5ac9f/html5/thumbnails/3.jpg)
17.3
17-1 CONNECTING DEVICES17-1 CONNECTING DEVICES
Connecting devices are used to connect hosts together to make a network or to connect networks together to make an internet.
![Page 4: Chapter 17 Connecting Devices And Virtual LANs Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display](https://reader033.vdocument.in/reader033/viewer/2022061522/56649f3c5503460f94c5ac9f/html5/thumbnails/4.jpg)
17.4
17-1 CONNECTING DEVICES17-1 CONNECTING DEVICES
Connecting devices can operate in different layers of the TCP/IP model.
![Page 5: Chapter 17 Connecting Devices And Virtual LANs Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display](https://reader033.vdocument.in/reader033/viewer/2022061522/56649f3c5503460f94c5ac9f/html5/thumbnails/5.jpg)
17.5
17-1 CONNECTING DEVICES17-1 CONNECTING DEVICES
three common connecting devices:
repeater-hubs, link-layer switches, and routers.
![Page 6: Chapter 17 Connecting Devices And Virtual LANs Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display](https://reader033.vdocument.in/reader033/viewer/2022061522/56649f3c5503460f94c5ac9f/html5/thumbnails/6.jpg)
17.6
Figure 17.1: Three categories of connecting devices
![Page 7: Chapter 17 Connecting Devices And Virtual LANs Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display](https://reader033.vdocument.in/reader033/viewer/2022061522/56649f3c5503460f94c5ac9f/html5/thumbnails/7.jpg)
17.7
17.17.1 Repeater-Hubs17.17.1 Repeater-Hubs
A repeater-hub is a multiport device that operates only in the physical layer.
Signals carrying information within a network can travel a fixed distance before attenuation endangers the integrity of the data.
![Page 8: Chapter 17 Connecting Devices And Virtual LANs Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display](https://reader033.vdocument.in/reader033/viewer/2022061522/56649f3c5503460f94c5ac9f/html5/thumbnails/8.jpg)
17.8
17.17.1 Repeater-Hubs17.17.1 Repeater-Hubs
A repeater receives a signal then regenerates and retimes the original bit pattern.
A repeater-hub (hub for short) is a multiport repeater.
The incoming signal is regenerated, retimed and sent through all ports excluding the entry port.
![Page 9: Chapter 17 Connecting Devices And Virtual LANs Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display](https://reader033.vdocument.in/reader033/viewer/2022061522/56649f3c5503460f94c5ac9f/html5/thumbnails/9.jpg)
17.9
Figure 17.2: Hub
![Page 10: Chapter 17 Connecting Devices And Virtual LANs Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display](https://reader033.vdocument.in/reader033/viewer/2022061522/56649f3c5503460f94c5ac9f/html5/thumbnails/10.jpg)
17.10
17.17.2 Link-Layer Switches17.17.2 Link-Layer Switches
A link-layer switch operates in both the physical and the data-link layers.
AKA, 2-layer switch
![Page 11: Chapter 17 Connecting Devices And Virtual LANs Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display](https://reader033.vdocument.in/reader033/viewer/2022061522/56649f3c5503460f94c5ac9f/html5/thumbnails/11.jpg)
17.11
17.17.2 Link-Layer Switches17.17.2 Link-Layer Switches
As a physical-layer device, it regenerates the signal it receives.
As a link-layer device, the link-layer switch can check the MAC addresses (source and destination) contained in the frame.
Some switches operate using virtual circuit identifiers or virtual path identifiers (or both).
![Page 12: Chapter 17 Connecting Devices And Virtual LANs Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display](https://reader033.vdocument.in/reader033/viewer/2022061522/56649f3c5503460f94c5ac9f/html5/thumbnails/12.jpg)
17.12
17.17.2 Link-Layer Switches17.17.2 Link-Layer Switches
Example (private Ethernet network with a 2-layer switch)
The switch table needs entries for each connected device MAC addresses and the corresponding port number.
MAC address: 48 bits, 12 nibbles, 6 octets.
![Page 13: Chapter 17 Connecting Devices And Virtual LANs Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display](https://reader033.vdocument.in/reader033/viewer/2022061522/56649f3c5503460f94c5ac9f/html5/thumbnails/13.jpg)
17.13
Figure 17.3: Link-Layer Switch
![Page 14: Chapter 17 Connecting Devices And Virtual LANs Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display](https://reader033.vdocument.in/reader033/viewer/2022061522/56649f3c5503460f94c5ac9f/html5/thumbnails/14.jpg)
17.14
17.17.2 Link-Layer Switches17.17.2 Link-Layer Switches
Example (private Ethernet network with a 2-layer switch)
A 2-layer switch is much smarter than a repeater(hub). The switch forwards the message through the appropriate port or ports as determined by the frame header fields.
![Page 15: Chapter 17 Connecting Devices And Virtual LANs Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display](https://reader033.vdocument.in/reader033/viewer/2022061522/56649f3c5503460f94c5ac9f/html5/thumbnails/15.jpg)
17.15
17.17.2 Learning Switch 17.17.2 Learning Switch
A learning switch can build a forwarding table by looking at the source address and corresponding port number.
Frames can be broadcast to the unassigned ports (like a hub) until all the ports are assigned. This can be accomplished with Switch Port Mapping Software
![Page 16: Chapter 17 Connecting Devices And Virtual LANs Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display](https://reader033.vdocument.in/reader033/viewer/2022061522/56649f3c5503460f94c5ac9f/html5/thumbnails/16.jpg)
17.16
17.17.2 Switch Software17.17.2 Switch Software
SNMP = Switch Network Mapping Protocol Managed Switch Port Mapping Tool NetDB = Network Tracking Database OpUtils Lan-sweeper
![Page 17: Chapter 17 Connecting Devices And Virtual LANs Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display](https://reader033.vdocument.in/reader033/viewer/2022061522/56649f3c5503460f94c5ac9f/html5/thumbnails/17.jpg)
17.17
Figure 17.4: Learning switch
![Page 18: Chapter 17 Connecting Devices And Virtual LANs Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display](https://reader033.vdocument.in/reader033/viewer/2022061522/56649f3c5503460f94c5ac9f/html5/thumbnails/18.jpg)
17.18
17.17.2 Switchs17.17.2 Switchs
Unmanaged switches – plug-n-play, without a management interface.
Managed switches – will include a command line interface.
• Smart switches• Managed switches
![Page 19: Chapter 17 Connecting Devices And Virtual LANs Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display](https://reader033.vdocument.in/reader033/viewer/2022061522/56649f3c5503460f94c5ac9f/html5/thumbnails/19.jpg)
17.19
Figure 17.5: Loop problem in a learning switch (Part a)
![Page 20: Chapter 17 Connecting Devices And Virtual LANs Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display](https://reader033.vdocument.in/reader033/viewer/2022061522/56649f3c5503460f94c5ac9f/html5/thumbnails/20.jpg)
17.20
Figure 17.5: Loop problem in a learning switch (Part b)
![Page 21: Chapter 17 Connecting Devices And Virtual LANs Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display](https://reader033.vdocument.in/reader033/viewer/2022061522/56649f3c5503460f94c5ac9f/html5/thumbnails/21.jpg)
17.21
Figure 17.5: Loop problem in a learning switch (Part c)
![Page 22: Chapter 17 Connecting Devices And Virtual LANs Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display](https://reader033.vdocument.in/reader033/viewer/2022061522/56649f3c5503460f94c5ac9f/html5/thumbnails/22.jpg)
17.22
Figure 17.5: Loop problem in a learning switch (part d)
![Page 23: Chapter 17 Connecting Devices And Virtual LANs Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display](https://reader033.vdocument.in/reader033/viewer/2022061522/56649f3c5503460f94c5ac9f/html5/thumbnails/23.jpg)
17.23
Figure 17.6: A system of connected LANs and its graph (Part a)
![Page 24: Chapter 17 Connecting Devices And Virtual LANs Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display](https://reader033.vdocument.in/reader033/viewer/2022061522/56649f3c5503460f94c5ac9f/html5/thumbnails/24.jpg)
Switch link assignment
Switch to Lan = 1 Lan to Switch = 0
![Page 25: Chapter 17 Connecting Devices And Virtual LANs Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display](https://reader033.vdocument.in/reader033/viewer/2022061522/56649f3c5503460f94c5ac9f/html5/thumbnails/25.jpg)
17.25
Figure 17.6: A system of connected LANs and its graph (Part b)
![Page 26: Chapter 17 Connecting Devices And Virtual LANs Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display](https://reader033.vdocument.in/reader033/viewer/2022061522/56649f3c5503460f94c5ac9f/html5/thumbnails/26.jpg)
17.26
Figure 17.7: Finding the shortest path and the spanning tree for a switch.
![Page 27: Chapter 17 Connecting Devices And Virtual LANs Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display](https://reader033.vdocument.in/reader033/viewer/2022061522/56649f3c5503460f94c5ac9f/html5/thumbnails/27.jpg)
17.27
Figure 17.8: Forwarding and blocking ports after using spanning
tree algorithm
![Page 28: Chapter 17 Connecting Devices And Virtual LANs Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display](https://reader033.vdocument.in/reader033/viewer/2022061522/56649f3c5503460f94c5ac9f/html5/thumbnails/28.jpg)
17.28
17.17.3 Routers17.17.3 Routers
We will discuss routers in Part IV of the book when we discuss the network layer.
![Page 29: Chapter 17 Connecting Devices And Virtual LANs Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display](https://reader033.vdocument.in/reader033/viewer/2022061522/56649f3c5503460f94c5ac9f/html5/thumbnails/29.jpg)
17.29
17.17.3 Routers17.17.3 Routers
A router is a three-layer device; it operates in the physical, data-link, and network layers.
![Page 30: Chapter 17 Connecting Devices And Virtual LANs Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display](https://reader033.vdocument.in/reader033/viewer/2022061522/56649f3c5503460f94c5ac9f/html5/thumbnails/30.jpg)
17.30
Figure 17.9: Routing example
![Page 31: Chapter 17 Connecting Devices And Virtual LANs Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display](https://reader033.vdocument.in/reader033/viewer/2022061522/56649f3c5503460f94c5ac9f/html5/thumbnails/31.jpg)
17.31
17-2 VIRTUAL LANS17-2 VIRTUAL LANS
A virtual local area network (VLAN) is a local area network configured by software, not by physical wiring.
![Page 32: Chapter 17 Connecting Devices And Virtual LANs Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display](https://reader033.vdocument.in/reader033/viewer/2022061522/56649f3c5503460f94c5ac9f/html5/thumbnails/32.jpg)
17.32
Figure 17.10: A switch connecting three LANs by wire
![Page 33: Chapter 17 Connecting Devices And Virtual LANs Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display](https://reader033.vdocument.in/reader033/viewer/2022061522/56649f3c5503460f94c5ac9f/html5/thumbnails/33.jpg)
17.33
Figure 17.11: A switch using VLAN software
![Page 34: Chapter 17 Connecting Devices And Virtual LANs Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display](https://reader033.vdocument.in/reader033/viewer/2022061522/56649f3c5503460f94c5ac9f/html5/thumbnails/34.jpg)
17.34
Figure 17.12: Two switches in a backbone using VLAN software
![Page 35: Chapter 17 Connecting Devices And Virtual LANs Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display](https://reader033.vdocument.in/reader033/viewer/2022061522/56649f3c5503460f94c5ac9f/html5/thumbnails/35.jpg)
17.35
17.2.1 Membership17.2.1 Membership
Characteristic used to group stations in a VLAN: ● interface numbers, ● port numbers, ● MAC addresses, ● IP addresses, ● or a combination of two or more of these.
![Page 36: Chapter 17 Connecting Devices And Virtual LANs Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display](https://reader033.vdocument.in/reader033/viewer/2022061522/56649f3c5503460f94c5ac9f/html5/thumbnails/36.jpg)
17.36
17.2.1 VLAN17.2.1 VLAN
VLANs …
●Save time and money because stations can be moved to any VLAN without re-wiring.
●Help manage network traffic
●Separate LANS for better security management