Chapter 3 Part 2 Switching and Bridging. Networking CS 3470, Section 1

Size: px
Start display at page:

Download "Chapter 3 Part 2 Switching and Bridging. Networking CS 3470, Section 1"

Transcription

1 Chapter 3 Part 2 Switching and Bridging Networking CS 3470, Section 1

2 Refresher We can use switching technologies to interconnect links to form a large network What is a hub? What is a switch? What is a bridge? Collision domains?

3 Hubs Hubs operate at the physical layer Why? They only repeat signals 3

4 Switches/Bridges Bridges (or switches) operate at the data link layer Why? They only make informed switching decisions using link layer addresses (typically MAC addresses) 4

5 Bridge Advantages Isolates collision domains resulting in higher total max throughput Limitless number of nodes and geographical coverage Can connect different Ethernet types Transparent ( plug-and-play ): no configuration necessary

6 Bridge Self Learning A bridge has a bridge table Entry in bridge table: (Node LAN Address, Bridge Interface, Time Stamp) Stale entries in table dropped (TTL can be 60 min) Bridges learn which hosts can be reached through which interfaces When frame received, bridge learns location of sender: incoming LAN segment Records sender/location pair in bridge table

7 Bridge Learning: Drawback Previous strategy works fine until a LAN has a loop in it Possible bad failure case frames could loop forever without getting to final destination! How could this happen? In a large network, some administrator could add a bridge that closes a loop without realizing it Could also be built in on purpose to provide redundancy 7

8 A Loop? Suppose all bridge table are empty Network J wants to send to Network E 8

9 A Loop? B4 does not know where E is at, so flood B2 does not know where E is at, so flood B6 does not know where E is at, so flood 9

10 Bridges Spanning Tree For increased reliability, desirable to have redundant, alternative paths from source to dest But we don t want the loop problem! Solution: organize bridges in a spanning tree by disabling subset of interfaces Disabled

11 Spanning Tree Algorithm Protocol used by set of bridges to agree upon a spanning tree for a particular LAN Each bridge decides the ports over which it is and is not willing to forward frames Algorithm is dynamic Bridges may reconfigure themselves into a new spanning tree should some bridge fail 11

12 Spanning Tree Algorithm Each bridge has a unique identifier B1, B2, B3 A B C E B3 B2 D B5 B7 F K G B1 H I B6 B4 J 12

13 Spanning Tree Algorithm Algorithm elects bridge with smallest ID as root of the spanning tree A B C E B3 B2 D B5 B7 F K G B1 H I B6 B4 J 13

14 Spanning Tree Algorithm The root bridge has all ports enabled. Each bridge computes the shortest path to the root and notes which port on that path. This is the preferred port to the root bridge. All bridges connected to the same LAN elect a single designated bridge to forward frames to the root bridge. If there's a tie, the one with the lowest ID wins.

15 Spanning Tree Algorithm While a human could have an overall view of the LAN and compute the spanning tree, bridges don t have that luxury Bridges must exchange configuration information with each other to decide root bridge and spanning tree 15

16 Configuration Messages Contain three things ID for bridge that is sending message (X) Distance (measured in hops) from sending bridge to the root bridge (d) ID for what sending bridge believes to be root bridge (Y) In form (Y,d,X) 16

17 Configuration Messages Initially, each bridge thinks it is the root Sends configuration messages out on each port identifying self as root and giving distance to the root as 0 17

18 Spanning Tree Algorithm A B C E B3 B2 D B5 B7 F K G B1 H I B6 B4 J

19 Spanning Tree Algorithm C A E B3 (B5,0,B5) (B2,0,B2) B2 (B3,0,B3) D (B3,0,B3) (B7,0,B7) B5 (B5,0,B5) B7 B F K G I B6 (B4,0,B4) B1 (B6,0,B6) (B4,0,B4) (B7,0,B7) (B2,0,B2) (B5,0,B5) (B6,0,B6) B4 H J

20 Configuration Messages Upon receiving messages, bridge checks to see if new message for port is better than currently recorded information Message is better if it Identifies a root with a smaller ID Identifies a root with equal ID but shorter distance Root ID and distance are equal, but sending bridge has smaller ID If message better, discard old information 20

21 Spanning Tree Algorithm C A E B3 (B5,0,B5) (B2,0,B2) B2 (B3,0,B3) D (B3,0,B3) (B7,0,B7) B5 (B5,0,B5) B7 B F K G I B6 (B4,0,B4) B1 (B6,0,B6) (B4,0,B4) (B7,0,B7) (B2,0,B2) (B5,0,B5) (B6,0,B6) B4 H J

22 Spanning Tree Algorithm C A E B3 (B5,0,B5) (B2,0,B2) B2 (B3,0,B3) D (B3,0,B3) (B7,0,B7) B5 (B5,0,B5) B7 B F K G I B6 (B4,0,B4) B1 (B6,0,B6) (B4,0,B4) (B7,0,B7) (B2,0,B2) (B5,0,B5)! (B6,0,B6) B4 H J

23 Configuration Messages When a bridge receives a message that it is not the root bridge It stops generating configuration messages on its own Only forwards configuration messages from other bridges after first adding 1 to the distance field 23

24 Spanning Tree Algorithm B3 has accepted B2 as root C A E B3 (B5,0,B5) (B2,0,B2) B2 (B3,0,B3) D (B3,0,B3) (B7,0,B7) B5 (B5,0,B5) B7 B F K G I B6 (B4,0,B4) B1 (B6,0,B6) (B4,0,B4) (B7,0,B7) (B2,0,B2) (B5,0,B5)! (B6,0,B6) B4 H J

25 Spanning Tree Algorithm B3 sends (B2,1,B3) towards B5 B2 accepts B1 as root and sends (B1,1,B2) towards B3 C A E B3 (B1,1,B5) (B1,1,B2) B2 (B2,1,B3) D (B2,1,B3) (B1,1,B7) B5 (B1,1,B5) B7 B F K G I B6 (B1,1,B4) B1 (B1,1,B6) (B1,1,B4) (B1,1,B7) (B1,1,B2) (B1,1,B5) (B1,1,B6) B4 H J

26 Spanning Tree Algorithm B5 accepts B1 as root and sends (B1,1,B5) towards B3 C A E B3 (B1,1,B5) (B1,1,B2) B2 (B2,1,B3) D (B2,1,B3) (B1,1,B7) B5 (B1,1,B5) B7 B F K G I B6 (B1,1,B4) B1 (B1,1,B6) (B1,1,B4) (B1,1,B7) (B1,1,B2) (B1,1,B5) (B1,1,B6) B4 H J

27 Spanning Tree Algorithm B3 accepts B1 as root Stops forwarding on both ports because B2 and B5 are closer to root B A C E B3 (B1,1,B5) (B1,1,B2) B2 (B2,1,B3) D (B2,1,B3) (B1,1,B7) B5 (B1,1,B5) B7 F K G I B6 (B1,1,B4) B1 (B1,1,B6) (B1,1,B4) (B1,1,B7) (B1,1,B2) (B1,1,B5) (B1,1,B6) B4 H J

28 A Loop? So how do we fix our first example s loop using spanning tree? 28

29 Limitations of Bridges Bridges only mean to connect a handful of similar LANs Spanning tree algorithm scales linearly At some point there are just too many messages Bridges forward all broadcast frames A different approach to increase the scalability of LANs is through the use of virtual LANs (VLANs) 29

30 VLANs IEEE 802.1Q standard VLANs separate the collision domain as well as the broadcast domain Hosts in each VLAN are in the same Virtual LAN Color coded Trunks carry multiple VLANs between switches A B E

31 VLANs Security Data on a VLAN is separated from other data VLAN can span multiple switches Example: Resnet Flexibility Now, users can connect to the closest switch and be put onto a VLAN with similar systems

32 VLANs VLAN tagged frames are carried as standard data link layer (802.3) frames Type field is modified from 0x8000 to 0x8100 DST and SRC addresses are preserved LEN/TYPE fields are modified to include the VLAN tag Data field is preserved TAG field adds 22 bytes to the frame

33 VLAN Notes 4096 VLANs allowed Most switches only support up to 1024 VLANs Spanning tree should be run on each VLAN

34 Routers Routers are nodes that interconnect networks Often called gateways Network layer device Why? Works with IP addresses Connects heterogeneous networks based off of different data link protocols Example? 34

35 Bridges vs. Routers Both store-and-forward devices Routers: network layer devices (examine network layer headers) Bridges are link layer devices Routers maintain routing tables, implement routing algorithms Bridges maintain bridge tables, implement filtering, learning and spanning tree algorithms

36 Routers vs. Bridges Bridges Pros Bridge operation is simpler requiring less packet processing Bridge tables are self learning Bridges Cons All traffic confined to spanning tree, even when alternative bandwidth is available Bridges do not offer protection from broadcast storms

37 Routers vs. Bridges Routers Pros Arbitrary topologies can be supported, cycling is limited by TTL counters (and good routing protocols) Provide protection against broadcast storms Routers Cons Require IP address configuration (not plug and play) Require higher packet processing

38 Routers vs. Bridges Bridges do well in small (few hundred hosts) while routers used in large networks (thousands of hosts) 38

Review. Error Detection: CRC Multiple access protocols. LAN addresses and ARP Ethernet. Slotted ALOHA CSMA/CD

Review. Error Detection: CRC Multiple access protocols. LAN addresses and ARP Ethernet. Slotted ALOHA CSMA/CD Review Error Detection: CRC Multiple access protocols Slotted ALOHA CSMA/CD LAN addresses and ARP Ethernet Some slides are in courtesy of J. Kurose and K. Ross Overview Ethernet Hubs, bridges, and switches

More information

Hubs. twisted pair. hub. 5: DataLink Layer 5-1

Hubs. twisted pair. hub. 5: DataLink Layer 5-1 Hubs Hubs are essentially physical-layer repeaters: bits coming from one link go out all other links at the same rate no frame buffering no CSMA/CD at : adapters detect collisions provides net management

More information

Data Link Layer. Our goals: understand principles behind data link layer services: instantiation and implementation of various link layer technologies

Data Link Layer. Our goals: understand principles behind data link layer services: instantiation and implementation of various link layer technologies Data Link Layer Our goals: understand principles behind data link layer services: link layer addressing instantiation and implementation of various link layer technologies 1 Outline Introduction and services

More information

Medium Access Protocols

Medium Access Protocols Medium Access Protocols Summary of MAC protocols What do you do with a shared media? Channel Partitioning, by time, frequency or code Time Division,Code Division, Frequency Division Random partitioning

More information

Principles behind data link layer services:

Principles behind data link layer services: Data link layer Goals: Principles behind data link layer services: Error detection, correction Sharing a broadcast channel: Multiple access Link layer addressing Reliable data transfer, flow control Example

More information

Principles behind data link layer services:

Principles behind data link layer services: Data link layer Goals: Principles behind data link layer services: Error detection, correction Sharing a broadcast channel: Multiple access Link layer addressing Reliable data transfer, flow control Example

More information

Principles behind data link layer services

Principles behind data link layer services Data link layer Goals: Principles behind data link layer services Error detection, correction Sharing a broadcast channel: Multiple access Link layer addressing Reliable data transfer, flow control: Done!

More information

Summary of MAC protocols

Summary of MAC protocols Summary of MAC protocols What do you do with a shared media? Channel Partitioning, by time, frequency or code Time Division, Code Division, Frequency Division Random partitioning (dynamic) ALOHA, S-ALOHA,

More information

Underlying Technologies -Continued-

Underlying Technologies -Continued- S465 omputer Networks Spring 2004 hapter 3 (Part B) Underlying Technologies -ontinued- Dr. J. Harrison These slides were produced from material by Behrouz Forouzan for the text TP/IP Protocol Suite (2

More information

Link layer: introduction

Link layer: introduction Link layer: introduction terminology: hosts and routers: nodes communication channels that connect adjacent nodes along communication path: links wired links wireless links LANs layer-2 packet: frame,

More information

Good day. Today we will be talking about Local Internetworking What is Internetworking? Internetworking is the connection of different networks.

Good day. Today we will be talking about Local Internetworking What is Internetworking? Internetworking is the connection of different networks. Computer Networks Prof: Sujoy Ghosh Department of Computer Science and Engineering Indian Institute of Technology, Kharagpur Lecture - 21 Local Internetworking Good day. Today we will be talking about

More information

ECE 4450:427/527 - Computer Networks Spring 2017

ECE 4450:427/527 - Computer Networks Spring 2017 ECE 4450:427/527 - Computer Networks Spring 2017 Dr. Nghi Tran Department of Electrical & Computer Engineering Lecture 6.1: Internetworking Dr. Nghi Tran (ECE-University of Akron) ECE 4450:427/527 Computer

More information

Hubs, Bridges, and Switches (oh my) Hubs

Hubs, Bridges, and Switches (oh my) Hubs Hubs, Bridges, and Switches (oh my) Used for extending LANs in terms of geographical coverage, number of nodes, administration capabilities, etc. Differ in regards to: collision domain isolation layer

More information

Lecture 7. Reminder: Homework 2, Programming Project 1 due today. Homework 3, Programming Project 2 out, due Thursday next week. Questions?

Lecture 7. Reminder: Homework 2, Programming Project 1 due today. Homework 3, Programming Project 2 out, due Thursday next week. Questions? Lecture 7 Reminder: Homework 2, Programming Project 1 due today. Homework 3, Programming Project 2 out, due Thursday next week. Questions? Thursday, September 15 CS 475 Networks - Lecture 7 1 Outline Chapter

More information

CSCI Computer Networks

CSCI Computer Networks CSCI-1680 - Computer Networks Link Layer III: LAN & Switching Chen Avin Based partly on lecture notes by David Mazières, Phil Levis, John Jannotti, Peterson & Davie, Rodrigo Fonseca Today: Link Layer (cont.)

More information

CSC 401 Data and Computer Communications Networks

CSC 401 Data and Computer Communications Networks CSC 401 Data and Computer Communications Networks Link Layer, Switches, VLANS, MPLS, Data Centers Sec 6.4 to 6.7 Prof. Lina Battestilli Fall 2017 Chapter 6 Outline Link layer and LANs: 6.1 introduction,

More information

Communication Networks ( ) / Spring 2011 The Blavatnik School of Computer Science, Tel-Aviv University. Allon Wagner

Communication Networks ( ) / Spring 2011 The Blavatnik School of Computer Science, Tel-Aviv University. Allon Wagner Communication Networks (0368-3030) / Spring 2011 The Blavatnik School of Computer Science, Tel-Aviv University Allon Wagner Kurose & Ross, Chapters 5.5-5.6 (5 th ed.) Tanenbaum & Wetherall, Chapters 4.3.4

More information

LAN Interconnection and Other Link Layer Protocols

LAN Interconnection and Other Link Layer Protocols LAN Interconnection and Other Link Layer Protocols Ethernet dominant link layer technology for local-area networks Ethernet frame structure Kai Shen Dept. of Computer Science, University of Rochester Ethernet

More information

CMPE 150 Winter 2009

CMPE 150 Winter 2009 CMPE 150 Winter 2009 Lecture 9 February 3, 2009 P.E. Mantey CMPE 150 -- Introduction to Computer Networks Instructor: Patrick Mantey mantey@soe.ucsc.edu http://www.soe.ucsc.edu/~mantey/ / t / Office: Engr.

More information

Telematics I. Chapter 6 Internetworking. (Acknowledement: These slides have been compiled from H. Karl s set of slides)

Telematics I. Chapter 6 Internetworking. (Acknowledement: These slides have been compiled from H. Karl s set of slides) Telematics I Chapter 6 Internetworking (Acknowledement: These slides have been compiled from H. Karl s set of slides) 1 Goals of This Chapter So far: we can communicate between nodes all connected directly

More information

CompSci 356: Computer Network Architectures. Lecture 8: Spanning Tree Algorithm and Basic Internetworking Ch & 3.2. Xiaowei Yang

CompSci 356: Computer Network Architectures. Lecture 8: Spanning Tree Algorithm and Basic Internetworking Ch & 3.2. Xiaowei Yang CompSci 356: Computer Network Architectures Lecture 8: Spanning Tree Algorithm and Basic Internetworking Ch 3.1.5 & 3.2 Xiaowei Yang xwy@cs.duke.edu Review Past lectures Single link networks Point-to-point,

More information

CompSci 356: Computer Network Architectures. Lecture 7: Switching technologies Chapter 3.1. Xiaowei Yang

CompSci 356: Computer Network Architectures. Lecture 7: Switching technologies Chapter 3.1. Xiaowei Yang CompSci 356: Computer Network Architectures Lecture 7: Switching technologies Chapter 3.1 Xiaowei Yang xwy@cs.duke.edu Types of switching Datagram Virtual circuit Source routing Today Bridges and LAN switches

More information

Some portions courtesy Srini Seshan or David Wetherall

Some portions courtesy Srini Seshan or David Wetherall CSE 123 Computer Networks Fall 2009 Lecture 6: Data-Link III: Hubs, Bridges and Switches Some portions courtesy Srini Seshan or David Wetherall Misc Homework solutions have been posted I ll post a sample

More information

EPL606. Internetworking. Part 2a. 1Network Layer

EPL606. Internetworking. Part 2a. 1Network Layer EPL606 Internetworking Part 2a The majority of the slides in this course are adapted from the accompanying slides to the books by Larry Peterson and Bruce Davie and by Jim Kurose and Keith Ross. Additional

More information

CSE 461: Bridging LANs. Last Topic

CSE 461: Bridging LANs. Last Topic CSE 461: Bridging LANs Last Topic Medium Access Control (MAC) protocols Part of the Link Layer At the heart of Local Area Networks (LANs) How do multiple parties share a wire or the air? Random access

More information

CS Networks and Distributed Systems. Lecture 5: Bridging. Revised 1/14/13

CS Networks and Distributed Systems. Lecture 5: Bridging. Revised 1/14/13 CS 3700 Networks and Distributed Systems Lecture 5: Bridging Revised 1/14/13 Just Above the Data Link Layer 2 Application Presentation Session Transport Network Data Link Physical Bridging! How do we connect

More information

Lecture 9: Switched Ethernet Features: STP and VLANs

Lecture 9: Switched Ethernet Features: STP and VLANs Lecture 9: Switched Ethernet Features: STP and VLANs Dr. Mohammed Hawa Electrical Engineering Department University of Jordan EE426: Communication Networks Ethernet Switch Features The following features

More information

Lecture 8: Networks to Internetworks

Lecture 8: Networks to Internetworks Lecture 8: Networks to Internetworks CSE 123: Computer Networks Alex C. Snoeren NO CLASS FRIDAY Lecture 8 Overview Bridging & switching Learning bridges Spanning Tree Internetworking Routering Internet

More information

Computer Networking. December 2004 CEN CN

Computer Networking. December 2004 CEN CN Computer Networking CEN CN 1 Layer 2 - Bridge Frame Header Data Bridge Trailer Data Link Layer Physical Layer More complex than repeat, it requires hardware and software Bridges have diminished because

More information

DD2490 p Layer 2 networking. Olof Hagsand KTH CSC

DD2490 p Layer 2 networking. Olof Hagsand KTH CSC DD2490 p4 2010 Layer 2 networking Olof Hagsand KTH CSC 1 Literature Radia Pearlman Interconnections - Bridges, Routers, Switches and Internetworking Protocols, Addison-Wesley. Section 3: Transparent bridges

More information

Internetworking Part 1

Internetworking Part 1 CMPE 344 Computer Networks Spring 2012 Internetworking Part 1 Reading: Peterson and Davie, 3.1 22/03/2012 1 Not all networks are directly connected Limit to how many hosts can be attached Point-to-point:

More information

More on Link Layer. Recap of Last Class. Interconnecting Nodes in LAN (Local-Area Network) Interconnecting with Hubs. Computer Networks 9/21/2009

More on Link Layer. Recap of Last Class. Interconnecting Nodes in LAN (Local-Area Network) Interconnecting with Hubs. Computer Networks 9/21/2009 More on Link Layer Kai Shen Recap of Last Class Ethernet dominant link layer technology for local-area l networks Ethernet frame structure Ethernet multiple access control CSMA/CD, exponential back-off

More information

Switching & ARP Week 3

Switching & ARP Week 3 Switching & ARP Week 3 Module : Computer Networks Lecturer: Lucy White lbwhite@wit.ie Office : 324 Many Slides courtesy of Tony Chen 1 Ethernet Using Switches In the last few years, switches have quickly

More information

CMPE 150/L : Introduction to Computer Networks. Chen Qian Computer Engineering UCSC Baskin Engineering Lecture 18

CMPE 150/L : Introduction to Computer Networks. Chen Qian Computer Engineering UCSC Baskin Engineering Lecture 18 CMPE 150/L : Introduction to Computer Networks Chen Qian Computer Engineering UCSC Baskin Engineering Lecture 18 1 Final project demo Please do the demo THIS week to the TAs. Or you are allowed to use

More information

Data Communications. Connecting Devices

Data Communications. Connecting Devices Data Communications Connecting Devices Connecting Devices Networks do not normally operate in isolation. They are connected to one another or to the Internet. To connect LANs, or segments of LANs, we use

More information

Introduction to OSPF

Introduction to OSPF Campus Networking Introduction to OSPF Workshop Campus Layer-2 Networking Network Workshop Design These materials are licensed under the Creative Commons Attribution-Noncommercial 3.0 Unported license

More information

CS3600 SYSTEMS AND NETWORKS

CS3600 SYSTEMS AND NETWORKS CS3600 SYSTEMS AND NETWORKS NORTHEASTERN UNIVERSITY Lecture 20: Bridging Prof. Alan Mislove (amislove@ccs.neu.edu) Slides used with permissions from Edward W. Knightly, T. S. Eugene Ng, Ion Stoica, Hui

More information

Chapter 6 Connecting Device

Chapter 6 Connecting Device Computer Networks Al-Mustansiryah University Elec. Eng. Department College of Engineering Fourth Year Class Chapter 6 Connecting Device 6.1 Functions of network devices Separating (connecting) networks

More information

CSE 123A Computer Networks

CSE 123A Computer Networks CSE 123A Computer Networks Winter 2005 Lecture 6: Data-Link III: Hubs, Bridges and Switches Some portions courtesy Srini Seshan or David Wetherall Last Time How do multiple hosts share a single channel?

More information

CS4700/CS5700 Fundamentals of Computer Networks

CS4700/CS5700 Fundamentals of Computer Networks CS4700/CS5700 Fundamentals of Computer Networks Lecture 9: Bridging Slides used with permissions from Edward W. Knightly, T. S. Eugene Ng, Ion Stoica, Hui Zhang Alan Mislove amislove at ccs.neu.edu Northeastern

More information

CS 43: Computer Networks Switches and LANs. Kevin Webb Swarthmore College December 5, 2017

CS 43: Computer Networks Switches and LANs. Kevin Webb Swarthmore College December 5, 2017 CS 43: Computer Networks Switches and LANs Kevin Webb Swarthmore College December 5, 2017 Ethernet Metcalfe s Ethernet sketch Dominant wired LAN technology: cheap $20 for NIC first widely used LAN technology

More information

6.1.2 Repeaters. Figure Repeater connecting two LAN segments. Figure Operation of a repeater as a level-1 relay

6.1.2 Repeaters. Figure Repeater connecting two LAN segments. Figure Operation of a repeater as a level-1 relay 6.1.2 Repeaters A single Ethernet segment can have a maximum length of 500 meters with a maximum of 100 stations (in a cheapernet segment it is 185m). To extend the length of the network, a repeater may

More information

CS 3516: Advanced Computer Networks

CS 3516: Advanced Computer Networks Welcome to CS 3516: Advanced Computer Networks Prof. Yanhua Li Time: 9:00am 9:50am M, T, R, and F Location: Fuller 320 Fall 2017 A-term 1 Some slides are originally from the course materials of the textbook

More information

Switching and Forwarding Reading: Chapter 3 1/30/14 1

Switching and Forwarding Reading: Chapter 3 1/30/14 1 Switching and Forwarding Reading: Chapter 3 1/30/14 1 Switching and Forwarding Next Problem: Enable communication between hosts that are not directly connected Fundamental Problem of the Internet or any

More information

CSCI-1680 Link Layer Wrap-Up Rodrigo Fonseca

CSCI-1680 Link Layer Wrap-Up Rodrigo Fonseca CSCI-1680 Link Layer Wrap-Up Rodrigo Fonseca Based partly on lecture notes by David Mazières, Phil Levis, John Janno< Administrivia Homework I out later today, due next Thursday, Sep 25th Today: Link Layer

More information

Computer Networks. Wenzhong Li. Nanjing University

Computer Networks. Wenzhong Li. Nanjing University Computer Networks Wenzhong Li Nanjing University 1 Chapter 2. Direct Link Networks Link Service and Framing Error Detection and Reliable Transmission HDLC, PPP, and SONET Token Ring Ethernet Bridges and

More information

L9: Bridges and LAN Switches. Hui Chen, Ph.D. Dept. of Engineering & Computer Science Virginia State University Petersburg, VA 23806

L9: Bridges and LAN Switches. Hui Chen, Ph.D. Dept. of Engineering & Computer Science Virginia State University Petersburg, VA 23806 L9: Bridges and LAN Switches Hui Chen, Ph.D. Dept. of Engineering & Computer Science Virginia State University Petersburg, VA 23806 1 Acknowledgements Some pictures used in this presentation were obtained

More information

Lecture 9: Bridging & Switching"

Lecture 9: Bridging & Switching Lecture 9: Bridging & Switching" CSE 123: Computer Networks Alex C. Snoeren HW 2 due Wednesday! Lecture 9 Overview" Finishing up media access Contention-free methods (rings) Moving beyond one wire Link

More information

CSCI-1680 Link Layer Wrap-Up Rodrigo Fonseca

CSCI-1680 Link Layer Wrap-Up Rodrigo Fonseca CSCI-1680 Link Layer Wrap-Up Rodrigo Fonseca Based partly on lecture notes by David Mazières, Phil Levis, John Jannotti Administrivia Homework I out later today, due next Thursday Today: Link Layer (cont.)

More information

Lecture 9 The Data Link Layer part II. Antonio Cianfrani DIET Department Networking Group netlab.uniroma1.it

Lecture 9 The Data Link Layer part II. Antonio Cianfrani DIET Department Networking Group netlab.uniroma1.it Lecture 9 The Data Link Layer part II Antonio Cianfrani DIET Department Networking Group netlab.uniroma1.it Physical Addresses Physical (or LAN or MAC) address: 48 bit string Hexadecimal representation

More information

CSCI-1680 Link Layer Wrap-Up Rodrigo Fonseca

CSCI-1680 Link Layer Wrap-Up Rodrigo Fonseca CSCI-1680 Link Layer Wrap-Up Rodrigo Fonseca Based partly on lecture notes by David Mazières, Phil Levis, John Janno< Administrivia Homework I out later today, due next ursday, Sep 27th Today: Link Layer

More information

Transparent Bridging and VLAN

Transparent Bridging and VLAN Transparent Bridging and VLAN Plug and Play Networking (C) Herbert Haas 2005/03/11 Algorhyme I think that I shall never see a graph more lovely than a tree a graph whose crucial property is loop-free connectivity.

More information

CSC 4900 Computer Networks: Link Layer (2)

CSC 4900 Computer Networks: Link Layer (2) CSC 4900 Computer Networks: Link Layer (2) Professor Henry Carter Fall 2017 Link Layer 6.1 Introduction and services 6.2 Error detection and correction 6.3 Multiple access protocols 6.4 LANs addressing,

More information

Lecture 10: Internetworking"

Lecture 10: Internetworking Lecture 10: Internetworking" CSE 123: Computer Networks Alex C. Snoeren HW 2 due NOW! Lecture 10 Overview" Spanning Tree Internet Protocol Service model Packet format 2 Spanning Tree Algorithm" Each bridge

More information

Configuring your VLAN. Presented by Gregory Laffoon

Configuring your VLAN. Presented by Gregory Laffoon Configuring your VLAN Presented by Gregory Laffoon 1 Overview of Networking Terms Networking Terms Overview OSI Model Defines a networking framework for implementing protocols in seven layers Control is

More information

Top-Down Network Design, Ch. 7: Selecting Switching and Routing Protocols. Top-Down Network Design. Selecting Switching and Routing Protocols

Top-Down Network Design, Ch. 7: Selecting Switching and Routing Protocols. Top-Down Network Design. Selecting Switching and Routing Protocols Top-Down Network Design Chapter Seven Selecting Switching and Routing Protocols Copyright 2010 Cisco Press & Priscilla Oppenheimer 1 Switching 2 Page 1 Objectives MAC address table Describe the features

More information

Chapter 5 part 2 LINK LAYER. Computer Networks Timothy Roscoe Summer Networks & Operating Systems Computer Networks

Chapter 5 part 2 LINK LAYER. Computer Networks Timothy Roscoe Summer Networks & Operating Systems Computer Networks Chapter 5 part 2 LINK LAYER Computer Networks Timothy Roscoe Summer 2007 LAN technologies Data link layer so far services, error detection/correction, multiple access Next: LAN technologies LAN addressing,

More information

The Link Layer and LANs: Ethernet and Swiches

The Link Layer and LANs: Ethernet and Swiches The Link Layer and LNs: Ethernet and Swiches EECS3214 2018-03-21 Link layer, LNs: outline 6.1 introduction, services 6.2 error detection, correction 6.3 multiple access protocols 6.4 LNs addressing, RP

More information

Top-Down Network Design

Top-Down Network Design Top-Down Network Design Chapter Seven Selecting Switching and Routing Protocols Original slides by Cisco Press & Priscilla Oppenheimer Selection Criteria for Switching and Routing Protocols Network traffic

More information

3. INTERCONNECTING NETWORKS WITH SWITCHES. THE SPANNING TREE PROTOCOL (STP)

3. INTERCONNECTING NETWORKS WITH SWITCHES. THE SPANNING TREE PROTOCOL (STP) 3. INTERCONNECTING NETWORKS WITH SWITCHES. THE SPANNING TREE PROTOCOL (STP) 3.1. STP Operation In an extended Ethernet network (a large network, including many switches) multipath propagation may exist

More information

LAN Overview (part 2) Interconnecting LANs - Hubs

LAN Overview (part 2) Interconnecting LANs - Hubs LAN Overview (part 2) CSE 3213 Fall 2011 1 November 2011 Interconnecting LANs - Hubs active central element of star layout each station connected to hub by two UTP lines hub acts as a repeater limited

More information

Campus Networking Workshop. Layer 2 engineering Spanning Tree and VLANs

Campus Networking Workshop. Layer 2 engineering Spanning Tree and VLANs Campus Networking Workshop Layer 2 engineering Spanning Tree and VLANs Switching Loop When there is more than one path between two switches What are the potential problems? Switching Loop If there is more

More information

A primer on modern LANs

A primer on modern LANs Advanced Networks http://disi.unitn.it/locigno/index.php/teaching-duties/ A primer on modern LANs Renato Lo Cigno Copyright Quest opera è prote1a dalla licenza: Crea&ve Commons A-ribuzione- Non commerciale-

More information

CSE 123: Computer Networks Alex C. Snoeren. HW 2 due Thursday 10/21!

CSE 123: Computer Networks Alex C. Snoeren. HW 2 due Thursday 10/21! CSE 123: Computer Networks Alex C. Snoeren HW 2 due Thursday 10/21! Finishing up media access Contention-free methods (rings) Moving beyond one wire Link technologies have limits on physical distance Also

More information

The following steps should be used when configuring a VLAN on the EdgeXOS platform:

The following steps should be used when configuring a VLAN on the EdgeXOS platform: EdgeXOS VLANs VLAN Overview This document provides an overview of what a VLAN is and how it is configured on the EdgeXOS platform. Use the step-by-step guide below to configure a VLAN on the Edge appliance

More information

Extending the LAN. Context. Info 341 Networking and Distributed Applications. Building up the network. How to hook things together. Media NIC 10/18/10

Extending the LAN. Context. Info 341 Networking and Distributed Applications. Building up the network. How to hook things together. Media NIC 10/18/10 Extending the LAN Info 341 Networking and Distributed Applications Context Building up the network Media NIC Application How to hook things together Transport Internetwork Network Access Physical Internet

More information

ECE 158A: Lecture 13. Fall 2015

ECE 158A: Lecture 13. Fall 2015 ECE 158A: Lecture 13 Fall 2015 Random Access and Ethernet! Random Access! Basic idea: Exploit statistical multiplexing Do not avoid collisions, just recover from them When a node has packet to send Transmit

More information

Administrivia. Homework on class webpage If you are having problems following me in class (or doing the homework problems), please buy the textbook

Administrivia. Homework on class webpage If you are having problems following me in class (or doing the homework problems), please buy the textbook Administrivia Homework on class webpage If you are having problems following me in class (or doing the homework problems), please buy the textbook Project Discussion class_ gotcha Reading finally on webpage

More information

Maintaining Specific VLAN Identification. Comparing ISL and 802.1Q. VLAN Trunking

Maintaining Specific VLAN Identification. Comparing ISL and 802.1Q. VLAN Trunking Maintaining Specific VLAN Identification Specifically developed for multi-vlan interswitch communications Places a unique identifier in each frame Functions at Layer 2 2003, Cisco Systems, Inc. All rights

More information

CSEP 561 LAN Switches. David Wetherall

CSEP 561 LAN Switches. David Wetherall CSEP 561 LAN Switches David Wetherall djw@cs.washington.edu How to combine links into a simple network Topics: Switch internals Plug and play LANs (switched Ethernet) Application Transport Network Building

More information

Top-Down Network Design

Top-Down Network Design Top-Down Network Design Chapter Five Designing a Network Topology Original slides copyright by Cisco Press & Priscilla Oppenheimer Network Topology Design Issues Hierarchy Redundancy Modularity Well-defined

More information

Token Ring VLANs and Related Protocols

Token Ring VLANs and Related Protocols Token Ring VLANs and Related Protocols CHAPTER 4 Token Ring VLANs A VLAN is a logical group of LAN segments, independent of physical location, with a common set of requirements. For example, several end

More information

Introduction to Communication Networks Spring Unit 13 Network extensions Bridges.

Introduction to Communication Networks Spring Unit 13 Network extensions Bridges. Introduction to Communication Networks Spring 2007 Unit 13 Network extensions Bridges. Acknowledgements slides coming from: The book by Peterson/Davie The book by Wiliam Stallings Slides from lectures

More information

Chapter 5. Spanning Tree Protocol (STP) Part I

Chapter 5. Spanning Tree Protocol (STP) Part I Chapter 5 Spanning Tree Protocol (STP) Part I CCNA3-1 Chapter 5-1 Note for Instructors These presentations are the result of a collaboration among the instructors at St. Clair College in Windsor, Ontario.

More information

EIGRP Features and Operation

EIGRP Features and Operation EIGRP Features and Operation Enhanced IGRP (EIGRP) is a classless, enhanced distance-vector protocol. EIGRP is a Cisco proprietary protocol. EIGRP includes the subnet mask in its route updates. And as

More information

Network Infrastructure

Network Infrastructure Network Infrastructure For building computer networks more complex than e.g. a short bus, some additional components are needed. They can be arranged hierarchically regarding their functionality: Repeater

More information

7010INT Data Communications Lecture 7 The Network Layer

7010INT Data Communications Lecture 7 The Network Layer Introduction 7010INT Data Communications Lecture 7 The Layer Internetworking & Devices Connecting LANs Routing Backbone networks Virtual LANs Addressing Application Presentation Session Data Link Physical

More information

Switching and bridging

Switching and bridging Switching and bridging CSCI 466: Networks Keith Vertanen Fall 2011 Last chapter: Overview Crea7ng networks from: Point- to- point links Shared medium (wireless) This chapter: SoCware and hardware connec7ng

More information

Switched Ethernet Virtual LANs

Switched Ethernet Virtual LANs Switched Ethernet Virtual LANs Computer Networks Lecture 4 http://goo.gl/pze5o8 Switched Ethernet 2 LAN Switches Behave as bridges (operates in the logical tree topology) Switching is implemented by hardware

More information

Lecture 4b. Local Area Networks and Bridges

Lecture 4b. Local Area Networks and Bridges Lecture 4b Local Area Networks and Bridges Ethernet Invented by Boggs and Metcalf in the 1970 s at Xerox Local area networks were needed to connect computers, share files, etc. Thick or Thin Ethernet Cable

More information

CS 455/555 Intro to Networks and Communications. Link Layer Addressing, Ethernet, and a Day in the Life of a Web Request

CS 455/555 Intro to Networks and Communications. Link Layer Addressing, Ethernet, and a Day in the Life of a Web Request CS 455/555 Intro to Networks and Communications Link Layer Addressing, ernet, and a Day in the Life of a Web Request Dr. Michele Weigle Department of Computer Science Old Dominion University mweigle@cs.odu.edu

More information

CCNA Cisco Certified Network Associate CCNA (v3.0)

CCNA Cisco Certified Network Associate CCNA (v3.0) 200-125 - CCNA Cisco Certified Network Associate CCNA (v3.0) 1.What is one benefit of PVST+? A. PVST+ supports Layer 3 load balancing without loops. B. PVST+ reduces the CPU cycles for all the switches

More information

Link Layer: CSMA/CD, MAC addresses, ARP

Link Layer: CSMA/CD, MAC addresses, ARP Link Layer: CSM/CD, MC addresses, RP Smith College, CSC 249 March 29, 208 MC ddress q 32-bit IP address: network-layer address used to get datagram to destination IP subnet q MC (or LN, physical, thernet,

More information

Chapter 5 Link Layer and LANs

Chapter 5 Link Layer and LANs Chapter 5 Link Layer and LANs A note on the use of these ppt slides: All material copyright 1996-2007 J.F Kurose and K.W. Ross, All Rights Reserved Computer Networking: A Top Down Approach 4 th edition.

More information

Layer 2 Engineering Spanning Tree

Layer 2 Engineering Spanning Tree Layer 2 Engineering Spanning Tree Campus Network Design & Operations Workshop These materials are licensed under the Creative Commons Attribution-NonCommercial 4.0 International license (http://creativecommons.org/licenses/by-nc/4.0/)

More information

Routing Between VLANs Overview

Routing Between VLANs Overview Routing Between VLANs Overview This chapter provides an overview of VLANs. It describes the encapsulation protocols used for routing between VLANs and provides some basic information about designing VLANs.

More information

Image courtesy Cisco Systems, Inc. Illustration of a Cisco Catalyst switch

Image courtesy Cisco Systems, Inc. Illustration of a Cisco Catalyst switch by Jeff Tyson If you have read other HowStuffWorks articles on networking or the Internet, then you know that a typical network consists of nodes (computers), a connecting medium (wired or wireless) and

More information

Spanning Trees and IEEE 802.3ah EPONs

Spanning Trees and IEEE 802.3ah EPONs Rev. 1 Norman Finn, Cisco Systems 1.0 Introduction The purpose of this document is to explain the issues that arise when IEEE 802.1 bridges, running the Spanning Tree Protocol, are connected to an IEEE

More information

Communication Networks

Communication Networks Communication Networks Spring 2018 Laurent Vanbever nsg.ee.ethz.ch ETH Zürich (D-ITET) March 19 2018 Materials inspired from Scott Shenker & Jennifer Rexford Last week on Communication Networks Reliable

More information

L2 Addressing and data plane. Benjamin Baron

L2 Addressing and data plane. Benjamin Baron L2 Addressing and data plane Benjamin Baron benjamin.baron@lip6.fr Goals of Today s Lecture Devices that shuttling packets at different layers - Repeaters and hubs - Bridges and switches - Routers Switch

More information

Bridging Transmitting Non-IP Traffic or Merging Two Networks

Bridging Transmitting Non-IP Traffic or Merging Two Networks 10 Bridging Transmitting Non-IP Traffic or Merging Two Networks Contents Overview..................................................... 10-3 Transmitting Non-IP Traffic..................................

More information

Switching and Forwarding

Switching and Forwarding Switching and Forwarding Outline Store-and-Forward Switches Bridges and Extended LANs Spring 7 CSE64 Switch Switching protocol T T STS- Spring 7 CSE64 Scalable Networks Switch forwards packets from input

More information

The Spanning Tree Protocol

The Spanning Tree Protocol Università Ca Foscari di Venezia Dipartimento di Informatica Corso di Sistemi Distribuiti 2009 Presentation outline Introduction 1 Introduction Local internetworking Motivations 2 High level description

More information

3.5 CONNECTING DEVICES

3.5 CONNECTING DEVICES 3.5 CONNECTING DEVICES LANs or WANs do not normally operate in isolation. They are connected to one another or to the Internet. To connect LANs and WANs together we use connecting devices. Connecting devices

More information

Lecture 6: Bridging & Switching. Last time. Today. CSE 123: Computer Networks Chris Kanich. How do multiple hosts share a single channel?

Lecture 6: Bridging & Switching. Last time. Today. CSE 123: Computer Networks Chris Kanich. How do multiple hosts share a single channel? Lecture 6: ridging & Switching SE 3: omputer Networks hris Kanich Project countdown: 5 days Last time How do multiple hosts share a single channel? Medium ccess ontrol (M) protocols hannel partitioning

More information

EXTENDING LAN winning the distance limitation

EXTENDING LAN winning the distance limitation CS 4/55231 Internet Engineering Kent State University Dept. of Computer Science LECT-5 WAN Extending LAN Techniques for extending LAN WAN Scalable Technologies to over come distance & number limitation

More information

Introduction. Network Architecture Requirements of Data Centers in the Cloud Computing Era

Introduction. Network Architecture Requirements of Data Centers in the Cloud Computing Era Massimiliano Sbaraglia Network Engineer Introduction In the cloud computing era, distributed architecture is used to handle operations of mass data, such as the storage, mining, querying, and searching

More information

Administrivia CSC458 Lecture 4 Bridging LANs and IP. Last Time. This Time -- Switching (a.k.a. Bridging)

Administrivia CSC458 Lecture 4 Bridging LANs and IP. Last Time. This Time -- Switching (a.k.a. Bridging) Administrivia CSC458 Lecture 4 Bridging LANs and IP Homework: # 1 due today # 2 out today and due in two weeks Readings: Chapters 3 and 4 Project: # 2 due next week Tutorial today: Joe Lim on project 2

More information

Outline. Routing. Introduction to Wide Area Routing. Classification of Routing Algorithms. Introduction. Broadcasting and Multicasting

Outline. Routing. Introduction to Wide Area Routing. Classification of Routing Algorithms. Introduction. Broadcasting and Multicasting Outline Routing Fundamentals of Computer Networks Guevara Noubir Introduction Broadcasting and Multicasting Shortest Path Unicast Routing Link Weights and Stability F2003, CSG150 Fundamentals of Computer

More information

Packet Switching Techniques

Packet Switching Techniques Packet Switching Techniques 188lecture3.ppt Pasi Lassila 1 Problem Aim: Build larger networks connecting more users also spanning different network technologies Shared media networks limited number of

More information