Lecture 9. Network Layer (cont d) Network Layer 1-1

Size: px
Start display at page:

Download "Lecture 9. Network Layer (cont d) Network Layer 1-1"

Transcription

1 Lecture 9 Network Layer (cont d) Network Layer 1-1

2 Agenda Routing Tables Unicast and Multicast Routing Protocols Routing Algorithms Link State and Distance Vector Routing Information and Open Shortest Path First Protocols Network Layer 1-2

3 Introduction to the Network Layer (Recall) transport segment from sending to receiving host on sending side encapsulates segments into datagrams on rcving side, delivers segments to transport layer layer protocols in every host, router router examines header fields in all IP datagrams passing through it application transport data link physical data link physical data link physical data link physical data link physical data link physical data link physical data link physical data link physical data link physical data link physical data link physical application transport data link physical Network Layer 5-3

4 Routing Tables A host or a router has a routing table with an entry for each destination, or a combination of destinations Routing tables: static (updated manually) or dynamic (updated automatically periodically) Routing methods Next-Hop Method Versus Route Method Network Layer 1-4

5 Routing Tables Routing methods Network-Specific Method Versus Host-Specific Method Network Layer 1-5

6 Interplay between Routing Algorithms and Forwarding Tables routing algorithm local forwarding table header value output link the job of routing algorithm is to determine good paths from senders to receivers, through a of routers Typically, a good path is one that has the least cost value in arriving packet s header Network Layer 4-6

7 Routing Protocols Routing protocols have been created in response to the demand for dynamic routing tables A routing protocol is a combination of rules and procedures that lets routers in the Internet inform each other of routing changes share whatever they know about the Internet or their neighborhood Unicast Routing Protocols Forwarding data packets from a source to a destination on a Multicast Routing Protocols Forwarding data packets from a source to multiple destinations Network Layer 1-7

8 Routing Protocols AS: Autonomous System Network Layer 1-8

9 Routing Problem Formulation (Graph abstraction) 2 u 1 Graph: G = (N,E) 5 v 3 w x y z Link s cost may reflect: - Link s physical length - The link speed - The monetary cost associated with a link N = set of routers = { u, v, w, x, y, z } E = set of links ={ (u,v), (u,x), (v,x), (v,w), (x,w), (x,y), (w,y), (w,z), (y,z) } Network Layer 4-9

10 Graph abstraction: costs 5 u 1 2 v x w y z c(x,x ) = cost of link (x,x ) = cost of link (x,x) - e.g., c(w,z) = c(z,w) = 5 Cost of path (x 1, x 2, x 3,, x p ) = c(x 1,x 2 ) + c(x 2,x 3 ) + + c(x p-1,x p ) Routing algorithm: algorithm that finds least-cost path Question: What s the least-cost (or shortest) path between u and z? Note: shortest path is the source-destination path with the smallest number of links Network Layer 4-10

11 Routing Algorithm Classification Global or decentralized information? Global: all routers have complete topology, link cost info (proactive algorithm) link state algorithms Decentralized: router knows physicallyconnected neighbors, link costs to neighbors iterative process of computation, exchange of info with neighbors distance vector algorithms Static or dynamic? Static: routes change slowly over time Suitable for proactive routing protocols Updates might not be req. Dynamic: routes change more quickly periodic update in response to link cost changes Network Layer 4-11

12 A Link-State Routing Algorithm net topology and link costs known to all nodes (global info.) accomplished via link state broadcast all nodes have same info Example: Open short path first (OSPF) routing protocol uses link-state routing algorithm such as Dijkstra s algorithm Dijkstra s algorithm computes least cost paths from one node ( source ) to all other nodes gives forwarding table for that node iterative: after k iterations, know least cost path to k destinations Algorithm complexity: n nodes n(n-1)/2 comparisons: O(n 2 ) polynomial complexity more efficient implementations possible: O(nlog(n)) Network Layer 4-12

13 Network Layer 4-13 Dijkstra s algorithm: example Step N' u ux uxy uxyv uxyvw uxyvwz D(v),p(v) 2,u 2,u 2,u D(w),p(w) 5,u 4,x 3,y 3,y D(x),p(x) 1,u D(y),p(y) 2,x D(z),p(z) 4,y 4,y 4,y u y x w v z

14 Distance Vector Algorithm Iterative, asynchronous, and distributed algorithm Distributed: node receives some information from one or more of its directly attached neighbors (decentralized information) Iterative: route discovery process continues on until no more information is exchanged between neighbors Asynchronous: does not require all of the nodes to operate in lockstep with each other From time-to-time, each node sends its own distance vector estimate to neighbors (e.g., may be at having link cost updates) Example: Bellman-Ford algorithm in Routing Information protocol (RIP) Define d x (y) := cost of least-cost path from x to y Then: d x (y) = min {c(x,v) + d v (y) } v where min is taken over all neighbors v of x Network Layer 4-14

15 Comparison of Link State (LS) and Distance Vector (DV) Algorithms Message complexity LS: with n nodes, E links, O(nE) msgs sent DV: exchange between neighbors only convergence time varies Speed of Convergence LS: O(n 2 ) algorithm requires O(nE) msgs may have oscillations DV: convergence time varies may be routing loops (count-to-infinity problem) Robustness: what happens if router malfunctions? LS: DV: node can advertise incorrect link cost each node computes only its own table DV node can advertise incorrect path cost each node s table used by others error propagate thru Network Layer 4-15

16 RIP ( Routing Information Protocol) distance vector algorithm included in Berkeley Software Distribution (BSD)- UNIX Distribution in 1982 distance metric: # of hops (max = 15 hops) From router A to subnets: z u A C B D v y w x destination hops u 1 v 2 w 2 x 3 y 3 z 2 Network Layer 4-16

17 RIP advertisements distance vectors: exchanged among neighbors every 30 sec via RIP Response Message (also called advertisement) each advertisement: contains a list of up to 25 destination subnets within AS as well as the sender s distance to each of those subnets If no advertisement heard after 180 sec --> neighbor/link declared dead routes via neighbor invalidated new advertisements sent to neighbors neighbors in turn send out new advertisements (if tables changed) Network Layer 4-17

18 RIP: Example z w x y A D B C Routing/Forwarding Table in Router D Destination Network Next Router Num. of hops to dest. w A 2 y B 2 z B 7 x Network Layer 4-18

19 RIP: Example Dest Next hops w - 1 x - 1 z C Advertisement from A to D w x y A D B z C Routing/Forwarding table in router D Destination Network Next Router Num. of hops to dest. w A 2 y B 2 z B A 7 5 x Network Layer 4-19

20 OSPF (Open Shortest Path First) open : publicly available typically deployed in upper-tier ISPs while RIP deployed in lowertier ISPs and enterprise s uses Link State algorithm LS packet dissemination (router floods routing information to all routers) topology map at each node route computation using Dijkstra s algorithm router broadcasts link state information whenever there is a change in a link s state (also broadcasts a link s state periodically) OSPF advertisement carries one entry per neighbor router advertisements disseminated to entire AS (via flooding) carried in OSPF messages directly over IP Network Layer 4-20

21 OSPF advanced features (not in RIP) Security all OSPF messages authenticated (to prevent malicious intrusion) Using authentication algorithms Multiple same-cost paths multiple same-cost paths allowed (only one path in RIP) Integrated support for unicast and multicast routing Multicast OSPF (MOSPF) uses the existing OSPF link database and adds a new type of link-state advertisement to the existing OSPF link-state broadcast mechanism Support for hierarchy within a single routing domain An OSPF autonomous system can be configured hierarchically into areas (more details in next slide) Network Layer 4-21

22 Internet Inter-AS routing: BGP BGP (Border Gateway Protocol) BGP provides each AS means to: 1. Obtain subnet reachability information from neighboring ASs. 2. Propagate reachability information to all ASinternal routers. 3. Determine good routes to subnets based on reachability information and policy. BGP allows subnet to advertise its existence to rest of Internet: I am here Network Layer 4-22

23 BGP basics pairs of routers (BGP peers) exchange routing info over semi-permanent TCP connections: BGP sessions 3c 3a 3b AS3 1a AS1 1c 1d ebgp session ibgp session 1b 2a 2c AS2 2b Network Layer 4-23

24 Broadcast Routing deliver packets from source to all other nodes source duplication is inefficient: duplicate R1 duplicate creation/transmission R1 R2 R2 duplicate R3 R4 R3 R4 source duplication in- duplication Network Layer 4-24

25 In- duplication flooding: when node receives broadcast packet, sends copy to all neighbors controlled flooding: node only broadcasts packet if it hasn t sent same packet before spanning tree No redundant packets received by any node Each node sends unicast join message to center node Network Layer 4-25

26 Multicast Routing: Problem Statement Goal: find a tree (or trees) connecting routers having local multicast group members tree: not all paths between routers used source-based tree: different tree from each sender to receivers Shared tree: same tree used by all group members Shared tree Source-based trees

27 Lecture Summary Covered material The Network Layer (cont d) Routing Tables Unicast and Multicast Routing Protocols Routing Algorithms Link State and Distance Vector Routing Information and Open Shortest Path First Protocols Material to be covered next lecture Introduction to the Transport Layer Network Layer 1-27

Lecture 4. The Network Layer (cont d)

Lecture 4. The Network Layer (cont d) Lecture 4 The Network Layer (cont d) Agenda Routing Tables Unicast and Multicast Routing Protocols Routing Algorithms Link State and Distance Vector Routing Information and Open Shortest Path First Protocols

More information

Chapter 4: Network Layer, partb

Chapter 4: Network Layer, partb Chapter 4: Network Layer, partb The slides are adaptations of the slides available by the main textbook authors, Kurose&Ross Network Layer 4-1 Interplay between routing, forwarding routing algorithm local

More information

Chapter 4 Network Layer

Chapter 4 Network Layer Chapter 4 Network Layer A note on the use of these ppt slides: We re making these slides freely available to all (faculty, students, readers). They re in PowerPoint form so you see the animations; and

More information

CMPE 80N: Introduction to Networking and the Internet. Katia Obraczka Computer Engineering UCSC Baskin Engineering Lecture 20

CMPE 80N: Introduction to Networking and the Internet. Katia Obraczka Computer Engineering UCSC Baskin Engineering Lecture 20 CMPE 80N: Introduction to Networking and the Internet Katia Obraczka Computer Engineering UCSC Baskin Engineering Lecture 0 Announcements Final exam: June 7 th at 4pm. Comprehensive. Photo id required.

More information

Chapter 5 Network Layer: The Control Plane

Chapter 5 Network Layer: The Control Plane Chapter 5 Network Layer: The Control Plane A note on the use of these Powerpoint slides: We re making these slides freely available to all (faculty, students, readers). They re in PowerPoint form so you

More information

Internet rou)ng. V. Arun CS491G: Computer Networking Lab University of MassachuseFs Amherst

Internet rou)ng. V. Arun CS491G: Computer Networking Lab University of MassachuseFs Amherst Internet rou)ng V. Arun CS491G: Computer Networking Lab University of MassachuseFs Amherst Slide material copyright 1996-2013 J.F Kurose and K.W. Ross, All Rights Reserved Graph abstraction 5 graph: G

More information

CSC 4900 Computer Networks: Routing Algorithms

CSC 4900 Computer Networks: Routing Algorithms CSC 4900 Computer Networks: Routing Algorithms Professor Henry Carter Fall 2017 Last Time Subnets provide granularity for address assignment and ease management. What is 192.168.8.0? 192.168.32.0? 192.168.8.0:

More information

Last time. Transitioning to IPv6. Routing. Tunneling. Gateways. Graph abstraction. Link-state routing. Distance-vector routing. Dijkstra's Algorithm

Last time. Transitioning to IPv6. Routing. Tunneling. Gateways. Graph abstraction. Link-state routing. Distance-vector routing. Dijkstra's Algorithm Last time Transitioning to IPv6 Tunneling Gateways Routing Graph abstraction Link-state routing Dijkstra's Algorithm Distance-vector routing Bellman-Ford Equation 10-1 This time Distance vector link cost

More information

DATA COMMUNICATOIN NETWORKING

DATA COMMUNICATOIN NETWORKING DATA COMMUNICATOIN NETWORKING Instructor: Ouldooz Baghban Karimi Course Book & Slides: Computer Networking, A Top-Down Approach By: Kurose, Ross Introduction Course Overview Basics of Computer Networks

More information

Hierarchical Routing. Our routing study thus far - idealization all routers identical network flat not true in practice

Hierarchical Routing. Our routing study thus far - idealization all routers identical network flat not true in practice Hierarchical Routing Our routing study thus far - idealization all routers identical network flat not true in practice scale: with 200 million destinations: can t store all destinations in routing tables!

More information

CSCE 463/612 Networks and Distributed Processing Spring 2018

CSCE 463/612 Networks and Distributed Processing Spring 2018 CSCE 463/612 Networks and Distributed Processing Spring 2018 Network Layer IV Dmitri Loguinov Texas A&M University April 12, 2018 Original slides copyright 1996-2004 J.F Kurose and K.W. Ross 1 Chapter

More information

Computer Networking Introduction

Computer Networking Introduction Computer Networking Introduction Halgurd S. Maghdid Software Engineering Department Koya University-Koya, Kurdistan-Iraq Lecture No.15 Chapter 4: outline 4.1 introduction 4.2 virtual circuit and datagram

More information

Chapter 4: outline. Network Layer 4-1

Chapter 4: outline. Network Layer 4-1 Chapter 4: outline 4.1 introduction 4.2 virtual circuit and datagram networks 4.3 what s inside a router 4.4 IP: Internet Protocol datagram format IPv4 addressing ICMP IPv6 4.5 routing algorithms link

More information

CSCD 330 Network Programming Spring 2018

CSCD 330 Network Programming Spring 2018 CSCD 330 Network Programming Spring 018 Lecture 16 Network Layer Routing Protocols Reading: Chapter 4 Some slides provided courtesy of J.F Kurose and K.W. Ross, All Rights Reserved, copyright 017 1 Network

More information

CSCD 330 Network Programming Spring 2017

CSCD 330 Network Programming Spring 2017 CSCD 330 Network Programming Spring 017 Lecture 16 Network Layer Routing Protocols Reading: Chapter 4 Some slides provided courtesy of J.F Kurose and K.W. Ross, All Rights Reserved, copyright 1996-007

More information

Chapter 4: Network Layer. Lecture 12 Internet Routing Protocols. Chapter goals: understand principles behind network layer services:

Chapter 4: Network Layer. Lecture 12 Internet Routing Protocols. Chapter goals: understand principles behind network layer services: NET 331 Computer Networks Lecture 12 Internet Routing Protocols Dr. Anis Koubaa Reformatted slides from textbook Computer Networking a top-down appraoch, Fifth Edition by Kurose and Ross, (c) Pearson Education

More information

ELEC / COMP 177 Fall Some slides from Kurose and Ross, Computer Networking, 5 th Edition

ELEC / COMP 177 Fall Some slides from Kurose and Ross, Computer Networking, 5 th Edition ELEC / COMP 177 Fall 01 Some slides from Kurose and Ross, Computer Networking, 5 th Edition Homework #4 Due Thursday, Nov 1 st Project # Due Tuesday, Nov 6 th Later this semester: Homework #5 Due Thursday,

More information

CSC 8560 Computer Networks: Control Plane

CSC 8560 Computer Networks: Control Plane CSC 8560 Computer Networks: Control Plane Professor Henry Carter Fall 2017 Last Time Subnets provide granularity for address assignment and ease management. What is 192.168.8.0? 192.168.32.0? 192.168.8.0:

More information

Chapter IV: Network Layer

Chapter IV: Network Layer Chapter IV: Network Layer UG3 Computer Communications & Networks (COMN) Myungjin Lee myungjin.lee@ed.ac.uk Slides copyright of Kurose and Ross Hierarchical routing our routing study thus far - idealization

More information

Data Communications & Networks. Session 7 Main Theme Networks: Part II Circuit Switching, Packet Switching, The Network Layer

Data Communications & Networks. Session 7 Main Theme Networks: Part II Circuit Switching, Packet Switching, The Network Layer Data Communications & Networks Session 7 Main Theme Networks: Part II Circuit Switching, Packet Switching, The Network Layer Dr. Jean-Claude Franchitti New York University Computer Science Department Courant

More information

Network Routing. Packet Routing, Routing Algorithms, Routers, Router Architecture

Network Routing. Packet Routing, Routing Algorithms, Routers, Router Architecture Network Routing Packet Routing, Routing Algorithms, Routers, Router Architecture Routing Routing protocol Goal: determine good path (sequence of routers) thru network from source to dest. Graph abstraction

More information

Network layer. Network Layer 4-1. application transport network data link physical. network data link physical. network data link physical

Network layer. Network Layer 4-1. application transport network data link physical. network data link physical. network data link physical Network layer transport segment from sending to receiving host on sending side encapsulates segments into datagrams on receiving side, delivers segments to transport layer network layer protocols in every

More information

Chapter 4: Network Layer

Chapter 4: Network Layer Chapter 4: Network Layer 4. 1 Introduction 4.2 Virtual circuit and datagram networks 4.3 What s inside a router 4.4 IP: Internet Protocol Datagram format IPv4 addressing ICMP IPv6 4.5 Routing algorithms

More information

CMPE 150/L : Introduction to Computer Networks. Chen Qian Computer Engineering UCSC Baskin Engineering Lecture 13

CMPE 150/L : Introduction to Computer Networks. Chen Qian Computer Engineering UCSC Baskin Engineering Lecture 13 CMPE 50/L : Introduction to Computer Networks Chen Qian Computer Engineering UCSC Baskin Engineering Lecture 3 Lab3 online Due March 4 th. Introduction -2 IP addresses: how to get one? Q: how does network

More information

CSc 450/550 Computer Networks Internet Routing

CSc 450/550 Computer Networks Internet Routing CSc 450/550 Computer Networks Internet Routing Jianping Pan Summer 2007 7/12/07 CSc 450/550 1 Review Internet Protocol (IP) IP header addressing class-based, classless, hierarchical, NAT routing algorithms

More information

Network layer: Overview. Network layer functions Routing IP Forwarding

Network layer: Overview. Network layer functions Routing IP Forwarding Network layer: Overview Network layer functions Routing IP Forwarding Network Layer Functions Transport packet from sending to receiving hosts Network layer protocols in every host, router application

More information

CSC 401 Data and Computer Communications Networks

CSC 401 Data and Computer Communications Networks CSC 40 Data and Computer Communications Networks Network Layer NAT, Routing, Link State, Distance Vector Prof. Lina Battestilli Fall 07 Chapter 4 Outline Network Layer: Data Plane 4. Overview of Network

More information

Interplay Between Routing, Forwarding

Interplay Between Routing, Forwarding Internet Routing 1 Interplay Between Routing, Forwarding routing algorithm local forwarding table header value output link 0100 0101 0111 1001 3 1 value in arriving packet s header 0111 3 1 Graph Abstraction

More information

Course on Computer Communication and Networks. Lecture 7 Network Layer, Chapter 4 (6/e) - Part B (7/e Ch5)

Course on Computer Communication and Networks. Lecture 7 Network Layer, Chapter 4 (6/e) - Part B (7/e Ch5) Course on Computer Communication and Networks Lecture 7 Network Layer, Chapter 4 (6/e) - Part B (7/e Ch5) EDA344/DIT 420, CTH/GU Based on the book Computer Networking: A Top Down Approach, Jim Kurose,

More information

DATA COMMUNICATOIN NETWORKING

DATA COMMUNICATOIN NETWORKING DATA COMMUNICATOIN NETWORKING Instructor: Ouldooz Baghban Karimi Course Book & Slides: Computer Networking, A Top-Down Approach By: Kurose, Ross Introduction Course Overview Basics of Computer Networks

More information

Chapter 4 Network Layer

Chapter 4 Network Layer Chapter 4 Network Layer CPSC 335 Data Communication Systems Readings: 4.4.3, 4.4.4, 4.5, 4.5.1 David Nguyen Computer Networking: A Top Down Approach 6 th edition Jim Kurose, Keith Ross Addison-Wesley March

More information

5.1 introduction 5.5 The SDN control 5.2 routing protocols plane. Control Message 5.3 intra-as routing in Protocol the Internet

5.1 introduction 5.5 The SDN control 5.2 routing protocols plane. Control Message 5.3 intra-as routing in Protocol the Internet Chapter 5: outline 5.1 introduction 5.5 The SDN control 5.2 routing protocols plane link state 5.6 ICMP: The Internet distance vector Control Message 5.3 intra-as routing in Protocol the Internet t 5.7

More information

EC441 Fall 2018 Introduction to Computer Networking Chapter 5: Network Layer Control Plane

EC441 Fall 2018 Introduction to Computer Networking Chapter 5: Network Layer Control Plane EC441 Fall 2018 Introduction to Computer Networking Chapter 5: Network Layer Control Plane This presentation is adapted from slides produced by Jim Kurose and Keith Ross for their book, Computer Networking:

More information

Initial motivation: 32-bit address space soon to be completely allocated. Additional motivation:

Initial motivation: 32-bit address space soon to be completely allocated. Additional motivation: IPv6 Initial motivation: 32-bit address space soon to be completely allocated. Additional motivation: header format helps speed processing/forwarding header changes to facilitate QoS IPv6 datagram format:

More information

Module 3 Network Layer CS755! 3-1!

Module 3 Network Layer CS755! 3-1! Module 3 Network Layer CS755 3-1 Please note: Most of these slides come from this book. Note their copyright notice below A note on the use of these ppt slides: We re making these slides freely available

More information

Network Layer: Routing

Network Layer: Routing Network Laer: Routing Instructor: Anirban Mahanti Office: ICT 74 Email: mahanti@cpsc.ucalgar.ca Class Location: ICT Lectures: MWF :00 :0 hours Notes derived Computer Networking: A Top Down Approach Featuring

More information

Chapter 4: outline. 4.5 routing algorithms link state distance vector hierarchical routing. 4.6 routing in the Internet RIP OSPF BGP

Chapter 4: outline. 4.5 routing algorithms link state distance vector hierarchical routing. 4.6 routing in the Internet RIP OSPF BGP Chapter 4: outline 4.1 introduction 4.2 virtual circuit and datagram networks 4.3 what s inside a router 4.4 IP: Internet Protocol datagram format IPv4 addressing ICMP IPv6 4.5 routing algorithms link

More information

Routing. Outline. Algorithms Scalability

Routing. Outline. Algorithms Scalability Routing Outline Algorithms Scalability 1 Internetworking What is internetwork An arbitrary collection of networks interconnected to provide some sort of host-host to packet delivery service A simple internetwork

More information

Chapter 4 Network Layer. Network Layer 4-1

Chapter 4 Network Layer. Network Layer 4-1 Chapter 4 Network Layer Network Layer 4- Chapter 4: Network Layer 4. Introduction 4. Virtual circuit and datagram networks 4. What s inside a router 4.4 IP: Internet Protocol Datagram format IPv4 addressing

More information

CSCE 463/612 Networks and Distributed Processing Spring 2017

CSCE 463/612 Networks and Distributed Processing Spring 2017 CSCE 46/6 Networks and Distributed Processing Spring 07 Network Layer III Dmitri Loguinov Texas A&M University April, 07 Original slides copyright 996-004 J.F Kurose and K.W. Ross Homework #4 Grading Default

More information

Internet Protocol: Routing Algorithms. Srinidhi Varadarajan

Internet Protocol: Routing Algorithms. Srinidhi Varadarajan Internet Protocol: Routing Algorithms Srinidhi Varadarajan Routing Routing protocol Goal: determine good path (sequence of routers) thru network from source to dest. Graph abstraction for routing algorithms:

More information

Department of Computer Science Southern Illinois University Carbondale

Department of Computer Science Southern Illinois University Carbondale Department of Computer Science Southern Illinois University Carbondale CS441 Mobile & Wireless Computing Overview of Computer Networking Network Layer of TCP/IP Model Data and Computer Communications 7

More information

CS 43: Computer Networks Internet Routing. Kevin Webb Swarthmore College November 14, 2013

CS 43: Computer Networks Internet Routing. Kevin Webb Swarthmore College November 14, 2013 CS 43: Computer Networks Internet Routing Kevin Webb Swarthmore College November 14, 2013 1 Reading Quiz Hierarchical routing Our routing study thus far - idealization all routers identical network flat

More information

CSCI Topics: Internet Programming Fall 2008

CSCI Topics: Internet Programming Fall 2008 CSCI 491-01 Topics: Internet Programming Fall 2008 Network Layer Derek Leonard Hendrix College November 17, 2008 Original slides copyright 1996-2007 J.F Kurose and K.W. Ross 1 Chapter 4: Roadmap 4.1 Introduction

More information

CSC 4900 Computer Networks: Routing Protocols

CSC 4900 Computer Networks: Routing Protocols CSC 4900 Computer Networks: Routing Protocols Professor Henry Carter Fall 2017 Last Time Link State (LS) versus Distance Vector (DV) algorithms: What are some of the differences? What is an AS? Why do

More information

Announcements. CS 5565 Network Architecture and Protocols. Project 2B. Project 2B. Project 2B: Under the hood. Routing Algorithms

Announcements. CS 5565 Network Architecture and Protocols. Project 2B. Project 2B. Project 2B: Under the hood. Routing Algorithms Announcements CS 5565 Network Architecture and Protocols Lecture 20 Godmar Back Project 2B due in 2 parts: Apr 29 and May 6 Extra Credit Opportunities: Expand simulator (and your implementation) to introduce

More information

Network layer: Overview. Network layer functions Routing IP Forwarding

Network layer: Overview. Network layer functions Routing IP Forwarding Network layer: Overview Network layer functions Routing IP Forwarding 1 Network Layer Functions Transport packet from sending to receiving hosts (processes) Network layer protocols in every host, router

More information

Chapter 4: Network Layer. TDTS06 Computer networks. Subnets. Subnets. Subnets. IP Addressing: introduction

Chapter 4: Network Layer. TDTS06 Computer networks. Subnets. Subnets. Subnets. IP Addressing: introduction hapter 4: Network Layer TDTS06 omputer s Lecture 6: Network layer III Routing in the Internet Jose M. Peña, jospe@ida.liu.se ID/DIT, LiU 2009-09-16 4. 1 Introduction 4.2 Virtual circuit and datagram s

More information

CS555, Spring /5/2005. April 12, 2005 No classes attend Senior Design Projects conference. Chapter 4 roadmap. Internet AS Hierarchy

CS555, Spring /5/2005. April 12, 2005 No classes attend Senior Design Projects conference. Chapter 4 roadmap. Internet AS Hierarchy CS555, Spring 2005 April 12, 2005 No classes attend Senior Design Projects conference Network Layer 4-1 Chapter 4 roadmap 4.1 Introduction and Network Service Models 4.2 VC and Datagram Networks 4.3 What

More information

Δίκτυα Υπολογιστών ΙΙ. Κώστας Μαγκούτης Επίκουρος Καθηγητής Τμήμα Μηχανικών Η/Υ και Πληροφορικής Πανεπιστήμιο Ιωαννίνων

Δίκτυα Υπολογιστών ΙΙ. Κώστας Μαγκούτης Επίκουρος Καθηγητής Τμήμα Μηχανικών Η/Υ και Πληροφορικής Πανεπιστήμιο Ιωαννίνων Δίκτυα Υπολογιστών ΙΙ Κώστας Μαγκούτης Επίκουρος Καθηγητής Τμήμα Μηχανικών Η/Υ και Πληροφορικής Πανεπιστήμιο Ιωαννίνων Course information introductory course in computer networking course materials: text:

More information

Dynamic Routing. The Protocols

Dynamic Routing. The Protocols Dynamic Routing The Protocols Desirable Characteristics of Dynamic Routing Automatically detect and adapt to topology changes Provide optimal routing Scalability Robustness Simplicity Rapid convergence

More information

Routing in the Internet

Routing in the Internet Routing in the Internet Daniel Zappala CS 460 Computer Networking Brigham Young University Scaling Routing for the Internet 2/29 scale 200 million destinations - can t store all destinations or all prefixes

More information

Chapter 4: Network Layer

Chapter 4: Network Layer Mecanismes d Echange d Informations Chapter 4 Network Layer A note on the use of these ppt slides: We re making these slides freely available to all (faculty, students, readers). They re in PowerPoint

More information

Computer Networks. Instructor: Niklas Carlsson

Computer Networks. Instructor: Niklas Carlsson Computer Networks Instructor: Niklas Carlsson Email: niklas.carlsson@liu.se Notes derived Computer Networking: A Top Down Approach, b Jim Kurose and Keith Ross, Addison-Wesle. The slides are adapted and

More information

Chapter 4 Network Layer

Chapter 4 Network Layer Chapter 4 Network Layer A note on the use of these ppt slides: We re making these slides freely available to all (faculty, students, readers). They re in PowerPoint form so you can add, modify, and delete

More information

CMPE 150/L : Introduction to Computer Networks. Chen Qian Computer Engineering UCSC Baskin Engineering Lecture 14

CMPE 150/L : Introduction to Computer Networks. Chen Qian Computer Engineering UCSC Baskin Engineering Lecture 14 CMPE 150/L : Introduction to Computer Networks Chen Qian Computer Engineering UCSC Baskin Engineering Lecture 14 1 Two notes on routing algorithm Do not believe ou can understand an routing protocol, e.g.,

More information

Chapter 4: Network Layer. Chapter 4: Network Layer

Chapter 4: Network Layer. Chapter 4: Network Layer Chapter 4: Network Layer Chapter goals: understand principles behind network layer services: network layer service models forwarding versus routing how a router works routing (path selection) dealing with

More information

Chapter 4: Network Layer. Chapter 4 Network Layer. Chapter 4: Network Layer. Network layer. Chapter goals:

Chapter 4: Network Layer. Chapter 4 Network Layer. Chapter 4: Network Layer. Network layer. Chapter goals: Chapter 4 Network Layer Computer Networking: A Top Down Approach Featuring the, 3 rd edition. Jim Kurose, Keith Ross Addison-Wesley, July 004. Chapter 4: Network Layer Chapter goals: understand principles

More information

Master Course Computer Networks IN2097

Master Course Computer Networks IN2097 Chair for Network Architectures and Services Prof. Carle Department for Computer Science TU München Master Course Computer Networks IN2097 Prof. Dr.-Ing. Georg Carle Christian Grothoff, Ph.D. Dr. Nils

More information

Chapter 4: Network Layer

Chapter 4: Network Layer Chapter 4: Network Laer 4. Introduction 4. Virtual circuit and datagram networks 4. What s inside a router 4.4 IP: Internet Protocol Datagram format IPv4 addressing ICMP IPv6 4. Routing algorithms Link

More information

Topics for This Week

Topics for This Week Topics for This Week Routing Protocols in the Internet OSPF, BGP More on IP Fragmentation and Reassembly ICMP Readings Sections 5.6.4-5.6.5 1 Hierarchical Routing aggregate routers into regions, autonomous

More information

Network Layer: Routing. Routing. Routing protocol. Graph abstraction for routing algorithms: graph nodes are routers graph edges are physical links

Network Layer: Routing. Routing. Routing protocol. Graph abstraction for routing algorithms: graph nodes are routers graph edges are physical links Network Layer: Routing A note on the use of these ppt slides: We re making these slides freely available to all (faculty, students, readers). They re in PowerPoint form so you can add, modify, and delete

More information

CS 457 Networking and the Internet. Shortest-Path Problem. Dijkstra s Shortest-Path Algorithm 9/29/16. Fall 2016

CS 457 Networking and the Internet. Shortest-Path Problem. Dijkstra s Shortest-Path Algorithm 9/29/16. Fall 2016 9/9/6 S 7 Networking and the Internet Fall 06 Shortest-Path Problem Given: network topology with link costs c(x,y): link cost from node x to node y Infinity if x and y are not direct neighbors ompute:

More information

Chapter 4 Network Layer

Chapter 4 Network Layer Chapter 4 Network Layer A note on the use of these ppt slides: We re making these slides freely available to all (faculty, students, readers). They re in PowerPoint form so you can add, modify, and delete

More information

Chapter 4 Network Layer

Chapter 4 Network Layer Chapter 4 Network Layer Computer Networking: A Top Down Approach 5th edition. Jim Kurose, Keith Ross Addison-Wesley, April 2009. All material copyright 1996-2009 J.F Kurose and K.W. Ross, All Rights Reserved

More information

Chapter 4 Network Layer

Chapter 4 Network Layer Chapter 4 Network Layer A note on the use of these ppt slides: We re making these slides freely available to all (faculty, students, readers). They re in PowerPoint form so you can add, modify, and delete

More information

CS 43: Computer Networks. 24: Internet Routing November 19, 2018

CS 43: Computer Networks. 24: Internet Routing November 19, 2018 CS 43: Computer Networks 24: Internet Routing November 19, 2018 Last Class Link State + Fast convergence (reacts to events quickly) + Small window of inconsistency Distance Vector + + Distributed (small

More information

CS 43: Computer Networks Internet Routing. Kevin Webb Swarthmore College November 16, 2017

CS 43: Computer Networks Internet Routing. Kevin Webb Swarthmore College November 16, 2017 CS 43: Computer Networks Internet Routing Kevin Webb Swarthmore College November 16, 2017 1 Hierarchical routing Our routing study thus far - idealization all routers identical network flat not true in

More information

Chapter 4 Network Layer. Chapter 4: Network Layer. Chapter 4: Network Layer. Chapter goals: understand principles behind network layer services:

Chapter 4 Network Layer. Chapter 4: Network Layer. Chapter 4: Network Layer. Chapter goals: understand principles behind network layer services: Chapter 4 Network Layer A note on the use of these ppt slides: We re making these slides freely available to all (faculty, students, readers). They re in PowerPoint form so you can add, modify, and delete

More information

Routing. Jens A Andersson Communication Systems

Routing. Jens A Andersson Communication Systems Routing Jens A Andersson Communication Systems R1 Choosing an Optimal Path R4 5 R7 5 10 40 R6 6 5 B R2 15 A 20 4 10 10 R8 R3 5 R5 10 Router A router is a type of internetworking device that passes data

More information

Chapter 4 Network Layer

Chapter 4 Network Layer Chapter 4 Network Layer Prof. Yuh-Shyan Chen Department of Computer Science and Information Engineering National Taipei University May 2007 Computer Networking: A Top Down Approach Featuring the Internet,

More information

Intra-AS Routing. Computer Networking: A Top Down Approach 6 th edition Jim Kurose, Keith Ross Addison-Wesley.

Intra-AS Routing. Computer Networking: A Top Down Approach 6 th edition Jim Kurose, Keith Ross Addison-Wesley. Intra-AS Routing Computer Networking: A Top Down Approach 6 th edition Jim Kurose, Keith Ross Addison-Wesle http://xkcd.com/85/ Some materials copright 1996-2012 J.F Kurose and K.W. Ross, All Rights Reserved

More information

Graph abstraction: costs. Graph abstraction 10/26/2018. Interplay between routing and forwarding

Graph abstraction: costs. Graph abstraction 10/26/2018. Interplay between routing and forwarding 0/6/08 Interpla between routing and forwarding Routing Algorithms Link State Distance Vector BGP routing routing algorithm local forwarding table header value output link 000 00 0 00 value in arriving

More information

Chapter 4 Network Layer

Chapter 4 Network Layer Chapter 4 Network Layer A note on the use of these ppt slides: We re making these slides freely available to all (faculty, students, readers). They re in PowerPoint form so you can add, modify, and delete

More information

Network service model. Network service model. Network Layer (part 1) Virtual circuits. By the end of this lecture, you should be able to.

Network service model. Network service model. Network Layer (part 1) Virtual circuits. By the end of this lecture, you should be able to. Netork Layer (part ) y the end of this lecture, you should be able to. xplain the operation of distance vector routing algorithm xplain shortest path routing algorithm escribe the major points of RIP and

More information

The Internet network layer

The Internet network layer The Internet network layer host, router network layer functions: transport layer: TCP, UDP network layer routing protocols path selection RIP, OSPF, BGP forwarding table link layer physical layer IP protocol

More information

ELEC / COMP 177 Fall Some slides from Kurose and Ross, Computer Networking, 5 th Edition

ELEC / COMP 177 Fall Some slides from Kurose and Ross, Computer Networking, 5 th Edition ELEC / COMP 177 Fall 2010 Some slides from Kurose and Ross, Computer Networking, 5 th Edition Project #2 Due Thursday, Nov 10 th Homework #5 Due Thursday, Nov 17 th Later this semester: Homework #6 - Presentation

More information

UNIT III THE NETWORK LAYER

UNIT III THE NETWORK LAYER UNIT III THE NETWORK LAYER Introduction-Virtual Circuit and Datagram Networks- Inside a Router- The Internet Protocol (IP): Forwarding and Addressing in the Internet-Routing Algorithms Routing in the Internet-Broadcast

More information

CMPT 371: Data Communications and Networking. Chapter 4: Network Layer

CMPT 371: Data Communications and Networking. Chapter 4: Network Layer School of Computing Science Simon Fraser University CMPT 371: Data Communications and Networking Chapter 4: Network Layer Network Layer 4-1 Chapter 4: Network Layer Chapter goals: understand principles

More information

Telecomunicazioni. Docente: Andrea Baiocchi. DIET - Stanza 107, 1 piano palazzina P. Piga Via Eudossiana 18

Telecomunicazioni. Docente: Andrea Baiocchi. DIET - Stanza 107, 1 piano palazzina P. Piga Via Eudossiana 18 University of Roma La Sapiena Telecomunicaioni Docente: Andrea Baiocchi DIET - Stana 07, piano palaina P. Piga Via Eudossiana 8 E-mail: andrea.baiocchi@uniroma.it Corso di Laurea in Ingegneria Gestionale

More information

Telecomunicazioni. Docente: Andrea Baiocchi DIET - Stanza 107, 1 piano palazzina P. Piga Via Eudossiana 18

Telecomunicazioni. Docente: Andrea Baiocchi DIET - Stanza 107, 1 piano palazzina P. Piga Via Eudossiana 18 University of Roma La Sapienza Telecomunicazioni Docente: Andrea Baiocchi DIET - Stanza 07, piano palazzina P. Piga Via Eudossiana 8 E-mail: andrea.baiocchi@uniroma.it Corso di Laurea in Ingegneria Gestionale

More information

CS118 Discussion 1A, Week 7. Zengwen Yuan Dodd Hall 78, Friday 10:00 11:50 a.m.

CS118 Discussion 1A, Week 7. Zengwen Yuan Dodd Hall 78, Friday 10:00 11:50 a.m. CS118 Discussion 1A, Week 7 Zengwen Yuan Dodd Hall 78, Friday 10:00 11:50 a.m. 1 Outline Network control plane Routing Link state routing (OSPF) Distance vector routing (RIP) BGP ICMP Midterm/Project 2

More information

Chapter 5 Network Layer: The Control Plane

Chapter 5 Network Layer: The Control Plane Chapter 5 Network Layer: The Control Plane A note on the use of these Powerpoint slides: We re making these slides freely available to all (faculty, students, readers). They re in PowerPoint form so you

More information

Chapter 5 Network Layer: The Control Plane

Chapter 5 Network Layer: The Control Plane Chapter 5 Network Layer: The Control Plane A note on the use of these Powerpoint slides: We re making these slides freely available to all (faculty, students, readers). They re in PowerPoint form so you

More information

Interplay between routing, forwarding

Interplay between routing, forwarding Chapter 4: outline 4. introduction 4. virtual circuit and datagram networks 4. what s inside a router 4.4 IP: Internet Protocol datagram format IPv4 addressing ICMP IPv6 4.5 routing algorithms link state

More information

Chapter 4 Network Layer

Chapter 4 Network Layer Chapter 4 Network Layer A note on the use of these ppt slides: We re making these slides freely available to all (faculty, students, readers). They re in PowerPoint form so you can add, modify, and delete

More information

COMPUTER NETWORKS CHAP 4 : NETWORK LAYER

COMPUTER NETWORKS CHAP 4 : NETWORK LAYER COMPUTER NETWORKS CHAP 4 : NETWORK LAYER 0160 08 h 12 h 29 Sep 2011 Chapter 4: 4-2 Chapter goals: understand principles behind network layer services: network layer service models forwarding versus routing

More information

All material copyright J.F Kurose and K.W. Ross, All Rights Reserved

All material copyright J.F Kurose and K.W. Ross, All Rights Reserved Computer Networks 1 (Mạng Máy Tính 1) Lectured by: Dr. Phạm Trần Vũ Chapter 4 Network Layer Computer Networking: A Top Down Approach, 5 th edition. Jim Kurose, Keith Ross Addison-Wesley, April 2009. All

More information

Chapter 5 Network Layer: The Control Plane

Chapter 5 Network Layer: The Control Plane Chapter 5 Network Layer: The Control Plane A note on the use of these Powerpoint slides: We re making these slides freely available to all (faculty, students, readers). They re in PowerPoint form so you

More information

Routing Unicast routing protocols

Routing Unicast routing protocols Routing Unicast routing protocols Jens A Andersson Electrical and Information Technology R1 Choosing an Optimal Path R4 5 R7 5 10 40 R6 6 5 B R2 15 A 20 4 10 10 R8 R3 5 10 R5 1 Router A router is a type

More information

Chapter 4 Network Layer

Chapter 4 Network Layer Chapter 4 Network Layer Computer Networking: A Top Down Approach 4 th edition. Jim Kurose, Keith Ross Addison-Wesley, July 2007. All material copyright 1996-2007 J.F Kurose and K.W. Ross, All Rights Reserved

More information

Lecture 19: Network Layer Routing in the Internet

Lecture 19: Network Layer Routing in the Internet Lecture 19: Network Layer Routing in the Internet COMP 332, Spring 2018 Victoria Manfredi Acknowledgements: materials adapted from Computer Networking: A Top Down Approach 7 th edition: 1996-2016, J.F

More information

Chapter 4: Network Layer. Chapter 4 Network Layer. Chapter 4: Network Layer. Network layer

Chapter 4: Network Layer. Chapter 4 Network Layer. Chapter 4: Network Layer. Network layer Chapter 4 Network Layer Computer Networking: A Top Down Approach 5 th edition. Jim Kurose, Keith Ross Addison-Wesley, April 009. Chapter 4: Network Layer Chapter goals: understand principles behind layer

More information

Chapter 5 Network Layer: The Control Plane

Chapter 5 Network Layer: The Control Plane Chapter 5 Network Layer: The Control Plane Lu Su Assistant Professor Department of Computer Science and Engineering State University of New York at Buffalo Adapted from the slides of the book s authors

More information

Inter-AS routing and BGP. Network Layer 4-1

Inter-AS routing and BGP. Network Layer 4-1 Inter-AS routing and BGP Network Layer 4-1 Review: intra-as routing v Also known as interior gateway protocols (IGP) v Most common intra-as routing protocols: RIP: Routing Information Protocol, distance

More information

Chapter 4 Network Layer

Chapter 4 Network Layer Chapter 4 Network Layer Computer Networking: A Top Down Approach 6 th edition Jim Kurose, Keith Ross Addison-Wesley March 2012 Slides adopted from original ones proided by the textbook authors. Network

More information

CS321: Computer Networks Unicast Routing

CS321: Computer Networks Unicast Routing CS321: Computer Networks Unicast Routing Dr. Manas Khatua Assistant Professor Dept. of CSE IIT Jodhpur E-mail: manaskhatua@iitj.ac.in Introduction The goal of the network layer is deliver a datagram from

More information

Chapter 4 Network Layer

Chapter 4 Network Layer Chapter 4 Network Layer A note on the use of these ppt slides: We re making these slides freely available to all (faculty, students, readers). They re in PowerPoint form so you can add, modify, and delete

More information

COMP211 Chapter 5 Network Layer: The Control Plane

COMP211 Chapter 5 Network Layer: The Control Plane COMP211 Chapter 5 Network Layer: The Control Plane All material copyright 1996-2016 J.F Kurose and K.W. Ross, All Rights Reserved Computer Networking: A Top Down Approach 7 th edition Jim Kurose, Keith

More information

Master Course Computer Networks IN2097

Master Course Computer Networks IN2097 Chair for Network Architectures and Services Prof. Carle Department for Computer Science TU München Master Course Computer Networks IN2097 Prof. Dr.-Ing. Georg Carle Christian Grothoff, Ph.D. Dr. Nils

More information