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

Size: px
Start display at page:

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

Transcription

1 University of Roma La Sapiena Telecomunicaioni Docente: Andrea Baiocchi DIET - Stana 07, piano palaina P. Piga Via Eudossiana 8 andrea.baiocchi@uniroma.it Corso di Laurea in Ingegneria Gestionale A.A. 03/04 Computers Computers make it easier to do a lot of things, but most of the things they make it easier to do don't need to be done. [Andy Rooney]

2 Programma. SERVIZI E RETI DI TELECOMUNICAZIONE. ARCHITETTURE DI COMUNICAZIONE 3. MODI DI TRASFERIMENTO 4. FONDAMENTI DI COMUNICAZIONI 5. LO STRATO DI COLLEGAMENTO 6. ACCESSO MULTIPLO 7. LO STRATO DI RETE IN INTERNET 8. LO STRATO DI TRASPORTO IN INTERNET Part of the slides are adapted from companion material of Chapter 4 (Network layer) of the book: Computer Networking: A Top Down Approach 4 th edition. Jim Kurose, Keith Ross Addison-Wesley, July 007.

3 Outline! 4. Internet architecture! 4. What s inside a router! 4.3 Internet Protocol (IP)! Datagram format! IPv4 addressing! ICMP! 4.4 Routing algorithms! Link state! Distance Vector! 4.5 Routing in the Internet! RIP! OSPF! BGP ICMP: Internet Control Message Protocol! Used by hosts & routers to communicate networklevel control information! error reporting: unreachable host, network, port, protocol! echo request/reply (used by ping)! ICMP msgs are carried in IP datagrams! ICMP message: type, code, plus first 8 bytes of IP datagram causing error Type Code description 0 0 echo reply (ping) 3 0 dest network unreachable 3 dest host unreachable 3 dest protocol unreachable 3 3 dest port unreachable 3 6 dest network unknown 3 7 dest host unknown 4 0 source quench (congestion control - not used) 8 0 echo request (ping) 9 0 route advertisement 0 0 router discovery 0 TTL expired 0 bad IP header

4 ICMP approach! ICMP aim is to notify mulfunctioning to the host originating the packet that triggered malfunctioning detection! It does not specify ensuing actions! It does not locate the source of the problem! e.g. intermediate system between packet origin and system detecting the error and issuing the ICMP msg! Each notification ICMP message is related to a specific IP packet

5 Traceroute! Source sends series of UDP segments to dest! First has TTL =, second has TTL=, etc.! Unlikely port number! When nth datagram arrives to nth router:! Router discards datagram and sends to source an ICMP message (type, code 0)! Message includes name of router & IP address! When ICMP message arrives, source calculates RTT! Traceroute does this 3 times Stopping criterion! UDP segment eventually arrives at destination host! Destination returns ICMP host unreachable packet (type 3, code 3)! When source gets this ICMP, stops. From my laptop, via IPsec, to US

6 From my laptop, via LAN to the server next building traceroute to ( ), 64 hops max, 40 byte packets ms.58 ms.88 ms ms 4.58 ms 4.03 ms ms 4.66 ms ms ms 4.96 ms ms ms 4.3 ms 4.7 ms ms 4.6 ms.356 ms ms 9.44 ms 7.99 ms ms 8.5 ms 8.39 ms ms.5 ms.65 ms PDU e bit! Trama di livello (Ethernet) che contiene un pacchetto IP, catturata da Wireshark! E una sequena di bit!!!! Caratteri hex per comodità ( hex = 4 bit) 00d9d8d734009df7bb c eaec0a8cd59c0a8cd008004d a6b6c6d6e6f Header Ethernet Payload Ethernet Header IP Payload IP 00d9d8d df7bb 0800=IP c0a8cd59 c0a8cd008 0=ICMP Header Payload ping request ICMP ICMP MAC MAC Protocol typeprotocol Indirio Indirio typeicmp IP IPType Destinaione Sorgente Sorgente Destinaione

7 Outline! 4. Internet architecture! 4. What s inside a router! 4.3 Internet Protocol (IP)! Datagram format! IPv4 addressing! ICMP! 4.4 Routing algorithms! Link state! Distance Vector! 4.5 Routing in the Internet! RIP! OSPF! BGP Interplay between routing, forwarding routing algorithm local forwarding table header value output link value in arriving packet s header 0 3

8 ARP: Address Resolution Protocol Question: how to determine MAC address of B knowing B s IP address? F7-B LAN A-F-BB AD D7-FA-0-B0! Each IP node (host, router) on LAN has ARP table! ARP table: IP/MAC address mappings for some LAN nodes < IP address; MAC address; TTL>! TTL (Time To Live): time after which address mapping will be forgotten (typically 0 min) C-C4--6F-E3-98 ARP cache (ARP table)! Updated each time an ARP request or ARP reply is read from the broadcast medium! Gratuitous ARP

9 ARP protocol: Same LAN (network)! A wants to send datagram to B, and B s MAC address not in A s ARP table.! A broadcasts ARP query packet, containing B's IP address! dest MAC address = FF-FF- FF-FF-FF-FF! all machines on LAN receive ARP query! B receives ARP packet, replies to A with its (B's) MAC address! frame sent to A s MAC address (unicast)! A caches (saves) IP-to-MAC address pair in its ARP table until information becomes old (times out)! soft state: information that times out (goes away) unless refreshed! ARP is plug-and-play :! nodes create their ARP tables without intervention from net administrator Addressing: routing to another LAN walkthrough: send datagram from A to B via R assume A knows B s IP address C-E8-FF-55 A... E6-E BB-4B A-3-F9-CD-06-9B 88-B-F-54-A-0F CC-49-DE-D0-AB-7D R... B 49-BD-D-C7-56-A! two ARP tables in router R, one for each subnet (LAN)

10 ! A creates IP datagram with source A, destination B! A uses ARP to get R s MAC address for...0! A creates link-layer frame with R's MAC address as dest, frame contains A-to-B IP datagram This is a really important! A s NIC sends frame example make sure you! R s NIC receives frame understand!! R removes IP datagram from Ethernet frame, sees its destined to B! R uses ARP to get B s MAC address! R creates frame containing A-to-B IP datagram sends to B C-E8-FF-55 A... E6-E BB-4B A-3-F9-CD-06-9B 88-B-F-54-A-0F CC-49-DE-D0-AB-7D R... B 49-BD-D-C7-56-A Graph abstraction 5 u v x 3 3 w y 5 Graph: G = (N,E) = (NODES, EDGES) N = set of routers = { u, v, w, x, y, } E = set of links ={ (u,v), (u,x), (v,x), (v,w), (x,w), (x,y), (w,y), (w,), (y,) } Remark: Graph abstraction is useful in other network contexts Example: PP, where N is set of peers and E is set of TCP connections; social networks where nodes are users and edges exist iff two users have a direct contact

11 Graph abstraction: costs 5 c(x,x ) = cost of link (x,x ) u v x 3 3 w y 5 - e.g., c(w,) = 5 cost could always be, or proportionl to link fee or inversely related to bandwidth, or inversely related to congestion Cost of path (x, x, x 3,, x p ) = c(x,x )+c(x,x 3 )+ +c(x p-,x p ) Question: What s the least-cost path between u and? Routing algorithm: algorithm that finds least-cost path Routing Algorithm classification Global or decentralied information? Global: ( link state algorithms)! all routers have complete topology, link cost info Decentralied:( distance vector algorithms)! router knows physically-connected neighbors, link costs to neighbors! iterative process of computation, exchange of info with neighbors Static or dynamic? Static: management plane! routes change only on network (re)-configuration Dynamic: control plane! routes change more quickly! periodic update! in response to link cost changes

12 Outline! 4. Internet architecture! 4. What s inside a router! 4.3 Internet Protocol (IP)! Datagram format! IPv4 addressing! ICMP! 4.4 Routing algorithms! Link state! Distance Vector! 4.5 Routing in the Internet! RIP! OSPF! BGP A Link-State Routing Algorithm Dijkstra s algorithm! net topology, link costs known to all nodes! accomplished via link state broadcast! all nodes have same info! 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 Notation:! c(x,y): link cost from node x to y; =! if not direct neighbors! D(v): current value of cost of path from source to dest. v! p(v): predecessor node along path from source to v! N': set of nodes whose least cost path definitively known

13 Dijsktra s Algorithm Initialiation: N' = {u} 3 for all nodes v 4 if v adjacent to u 5 then D(v) = c(u,v) and p(v)=u 6 else D(v) =! 8 Loop 9 find w not in N' such that D(w) is a minimum 0 add w to N' update D(v) for all v adjacent to w and not in N' : D(v) = min{ D(v), D(w) + c(w,v) ) 3 if D(w)+c(w,v) < D(v) then p(v)=w 4 /* new cost to v is either old cost to v or known 4 shortest path cost to w plus cost from w to v */ 5 until all nodes in N' Dijkstra s algorithm: example Step N' u ux uxy uxyv uxyvw uxyvw D(v),p(v),u,u,u D(w),p(w) 5,u 4,x 3,y 3,y D(x),p(x),u D(y),p(y)!,x D(),p()!! 4,y 4,y 4,y 5 u v x 3 3 w y 5

14 Dijkstra s algorithm: example () Resulting shortest-path tree from u: v w u x y Resulting forwarding table in u: destination v x y w link (u,v) (u,x) (u,x) (u,x) (u,x) Dijkstra s algorithm, discussion Algorithm complexity: n nodes! each iteration: need to check all nodes, w, not in N! n(n+)/ comparisons: O(n )! more efficient implementations possible: O(n logn) Oscillations possible:! e.g., link cost = amount of carried traffic A +e D 0 0 B 0 e C e initially +e A 0 D B 0 +e 0 C recompute routing 0 A +e D 0 0 B C +e recompute +e A 0 D B 0 +e 0 C recompute

15 Outline! 4. Internet architecture! 4. What s inside a router! 4.3 Internet Protocol (IP)! Datagram format! IPv4 addressing! ICMP! 4.4 Routing algorithms! Link state! Distance Vector! 4.5 Routing in the Internet! RIP! OSPF! BGP Distance Vector Algorithm Bellman-Ford Equation (dynamic programming) 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

16 Bellman-Ford example u 5 Assume we know that d v () = 5, d x () = 3, d w () = 3 v x 3 3 w y 5 B-F equation says: d u () = min { c(u,v) + d v (), c(u,x) + d x (), c(u,w) + d w () } = min { + 5, + 3, 5 + 3} = 4 Node that achieves minimum is next hop in shortest path!"forwarding table Distance Vector Algorithm! D x (y) = estimate of least cost from x to y! Node x knows cost to each neighbor v: c(x,v)! Node x maintains distance vector DV D x = [D x (y): y " N ]! Node x also maintains its neighbors distance vectors: for each neighbor v, x maintains D v = [D v (y): y " N ]

17 Distance vector algorithm (4) Basic idea:! From time-to-time, each node sends its own distance vector estimate to neighbors! Asynchronous update! When a node x receives new DV estimate from neighbor, it updates its own DV using B-F equation: D x (y)! min v {c(x,v) + D v (y)} for each node y! N! Neighbor v* attaining minimum for destination y is next hop to y! Under minor, natural conditions, the estimate D x (y) converge to the actual least cost d x (y) Distance Vector Algorithm (5) Iterative, asynchronous:! Each local iteration caused by:! local link cost change! DV update message from neighbor Distributed:! each node notifies neighbors only when its DV changes! neighbors then notify their neighbors if necessary Each node: wait for (change in local link cost or msg from neighbor) recompute estimates if DV to any dest has changed, notify neighbors

18 D x (y) = min{c(x,y) + D y (y), c(x,) + D (y)} = min{+0, 7+} = node x table cost to cost to x y x y x 0 7 y!!!!!! node y table cost to x y from from from x y!!! 0!!! node table cost to x y x!!! y!!! 7 0 from x y time D x () = min{c(x,y) + D y (), c(x,) + D ()} = min{+, 7+0} = 3 x y 7 D x (y) = min{c(x,y) + D y (y), c(x,) + D (y)} = min{+0, 7+} = node x table cost to cost to cost to x y x y x y x 0 7 x 0 3 x 0 3 y!!! y 0 y 0!!! node y table cost to cost to cost to x y x y x y x!!! x 0 7 x 0 3 y 0 y 0 y 0!!! from from node table cost to x y from x!!! y!!! 7 0 from from from cost to x y x y from from from x y cost to x y time D x () = min{c(x,y) + D y (), c(x,) + D ()} = min{+, 7+0} = 3 x y 7

19 Distance Vector: link cost changes Link cost changes:! node detects local link cost change! updates routing info, recalculates distance vector! if DV changes, notify neighbors x 4 y 50 good news travels fast At time t 0, y detects the link-cost change, updates its DV, and informs its neighbors. At time t, receives the update from y and updates its table. It computes a new least cost to x and sends its neighbors its DV. At time t, y receives s update and updates its distance table. y s least costs do not change and hence y does not send any message to. Distance Vector: link cost changes Link cost changes:! good news travels fast! bad news travels slow - count to infinity problem!! 44 iterations before algorithm stabilies: see text 60 x 4 y 50 Poisoned reverse:! If Z routes through Y to get to X :! Z tells Y its (Z s) distance to X is infinite (so Y won t route to X via Z)! will this completely solve count to infinity problem?

20 Comparison of LS and 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 ) 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 Outline! 4. Internet architecture! 4. What s inside a router! 4.3 Internet Protocol (IP)! Datagram format! IPv4 addressing! ICMP! 4.4 Routing algorithms! Link state! Distance Vector! 4.5 Routing in the Internet! RIP! OSPF! BGP

21 Intra-AS Routing! also known as Interior Gateway Protocols (IGP)! most common Intra-AS routing protocols:! RIP: Routing Information Protocol! OSPF: Open Shortest Path First! IGRP: Interior Gateway Routing Protocol (Cisco proprietary) RIP (Routing Information Protocol)! distance vector algorithm! included in BSD-UNIX Distribution in 98! distance metric: # of hops (max = 5 hops) From router A to subnets: u A C B D v y w x destination hops u v w x 3 y 3

22 RIP advertisements! distance vectors: exchanged among neighbors every 30 sec via Response Message (also called advertisement)! each advertisement: list of up to 5 destination subnets within AS RIP: Example w x y A D B C Destination Network Next Router Num. of hops to dest. w A y B B 7 x Routing/Forwarding table in D

23 RIP: Example Dest Next hops w - x - C Advertisement from A to D w x y A D B C Destination Network Next Router Num. of hops to dest. w A y B B A 7 5 x Routing/Forwarding table in D RIP: Link Failure and Recovery If no advertisement heard after 80 sec --> neighbor/link declared dead! routes via neighbor invalidated! new advertisements sent to neighbors! neighbors in turn send out new advertisements (if tables changed)! link failure info quickly (?) propagates to entire net! poison reverse used to prevent ping-pong loops (infinite distance = 6 hops)

24 RIP Table processing! RIP routing tables managed by application-level process called route-d (daemon)! advertisements sent in UDP packets, periodically repeated route-d route-d Transport (UDP) Transport (UDP) network (IP) forwarding table forwarding table network (IP) link link physical physical Outline! 4. Internet architecture! 4. What s inside a router! 4.3 Internet Protocol (IP)! Datagram format! IPv4 addressing! ICMP! 4.4 Routing algorithms! Link state! Distance Vector! 4.5 Routing in the Internet! RIP! OSPF! BGP

25 OSPF (Open Shortest Path First)! open : publicly available! uses Link State algorithm! LS packet dissemination! topology map at each node! route computation using Dijkstra s algorithm! OSPF advertisement carries one entry per neighbor router! advertisements disseminated to entire AS (via flooding)! carried in OSPF messages directly over IP (rather than TCP or UDP OSPF advanced features (not in RIP)! security: all OSPF messages authenticated (to prevent malicious intrusion)! multiple same-cost paths allowed (only one path in RIP)! For each link, multiple cost metrics for different TOS (e.g., satellite link cost set low for best effort; high for real time)! integrated uni- and multicast support:! Multicast OSPF (MOSPF) uses same topology data base as OSPF! hierarchical OSPF in large domains.

26 Hierarchical OSPF Hierarchical OSPF! two-level hierarchy: local area, backbone.! Link-state advertisements only in area! each nodes has detailed area topology; only know direction (shortest path) to nets in other areas.! area border routers: summarie distances to nets in own area, advertise to other Area Border routers.! backbone routers: run OSPF routing limited to backbone.! boundary routers: connect to other AS s.

27 Outline! 4. Internet architecture! 4. What s inside a router! 4.3 Internet Protocol (IP)! Datagram format! IPv4 addressing! ICMP! 4.4 Routing algorithms! Link state! Distance Vector! 4.5 Routing in the Internet! RIP! OSPF! BGP Internet inter-as routing: BGP! BGP (Border Gateway Protocol): the de facto standard! BGP provides each AS a means to:. Obtain subnet reachability information from neighboring ASs.. Propagate reachability information to all ASinternal routers. 3. Determine good routes to subnets based on reachability information and policy.! allows subnet to advertise its existence to rest of Internet: I am here

28 BGP basics! pairs of routers (BGP peers) exchange routing info over semi-permanent TCP connections: BGP sessions! BGP sessions need not correspond to physical links.! when AS advertises a prefix to AS:! AS promises it will forward datagrams towards that prefix.! AS can aggregate prefixes in its advertisement 3c 3a 3b AS3 a AS c d ebgp session ibgp session b a c b AS Distributing reachability info! using ebgp session between 3a and c, AS3 sends prefix reachability info to AS.! c can then use ibgp to distribute new prefix info to all routers in AS! b can then re-advertise new reachability info to AS over b-to-a ebgp session! when router learns of new prefix, it creates entry for prefix in its forwarding table. 3c 3a 3b AS3 a AS c b d ebgp session ibgp session a c b AS

29 Path attributes & BGP routes! advertised prefix includes BGP attributes.! prefix + attributes = route! two important attributes:! AS-PATH: contains ASs through which prefix advertisement has passed: e.g, AS 67, AS 7! NEXT-HOP: indicates specific internal-as router to next-hop AS. (may be multiple links from current AS to next-hop-as)! when gateway router receives route advertisement, uses import policy to accept/decline. BGP route selection! router may learn about more than route to some prefix. Router must select route.! elimination rules:. local preference value attribute: policy decision. shortest AS-PATH 3. closest NEXT-HOP router: hot potato routing 4. additional criteria

30 BGP messages! BGP messages exchanged using TCP.! BGP messages:! OPEN: opens TCP connection to peer and authenticates sender! UPDATE: advertises new path (or withdraws old)! KEEPALIVE keeps connection alive in absence of UPDATES; also ACKs OPEN request! NOTIFICATION: reports errors in previous msg; also used to close connection BGP routing policy (/) W A B C X legend: provider network customer network: Y! A,B,C are provider networks! X,W,Y are customer (of provider networks)! X is dual-homed: attached to two networks! X does not want to route from B via X to C!.. so X will not advertise to B a route to C

31 BGP routing policy (/) W A B C X legend: provider network customer network:! A advertises path AW to B! B advertises path BAW to X! Should B advertise path BAW to C?! No way! B gets no revenue for routing CBAW since neither W nor C are B s customers! B wants to force C to route to W via A! B wants to route only to/from its customers! Y Why different Intra- and Inter-AS routing? Policy:! Inter-AS: admin wants control over how its traffic routed, who routes through its net.! Intra-AS: single admin, so no policy decisions needed Scale:! hierarchical routing saves table sie, reduced update traffic Performance:! Intra-AS: can focus on performance! Inter-AS: policy may dominate over performance

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Lecture 9. Network Layer (cont d) Network Layer 1-1 Lecture 9 Network Layer (cont d) Network Layer 1-1 Agenda Routing Tables Unicast and Multicast Routing Protocols Routing Algorithms Link State and Distance Vector Routing Information and Open Shortest

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 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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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 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

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

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

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 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

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

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

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

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

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

Chapter 4: Network Layer: Part II

Chapter 4: Network Layer: Part II 4: Network Laer Chapter 4: Network Laer: Part II (last revision 9/04/05. v3) 4. Introduction 4. Virtual circuit and datagram networks 4.3 What s inside a router 4.4 IP: Internet Protocol Datagram format

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

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. 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

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

Inter-AS routing. Computer Networking: A Top Down Approach 6 th edition Jim Kurose, Keith Ross Addison-Wesley Inter-AS routing Computer Networking: A Top Down Approach 6 th edition Jim Kurose, Keith Ross Addison-Wesley Some materials copyright 1996-2012 J.F Kurose and K.W. Ross, All Rights Reserved Chapter 4:

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

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

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

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

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

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

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 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

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. 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

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

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

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

Network Layer: Control Plane 5-2

Network Layer: Control Plane 5-2 Network Laer: Control Plane EECS34 8-03-05 4- Chapter 5: network laer control plane chapter goals: understand principles behind network control plane traditional routing algorithms SDN controlllers Internet

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

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

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

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

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

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

11/13/2017 Network Layer (SSL) Network-layer functions. Recall the two network-layer functions:

11/13/2017 Network Layer (SSL) Network-layer functions. Recall the two network-layer functions: Chapter 5: outline 5. introduction 5.2 routing protocols link state distance vector 5.3 intra-as routing in the Internet 5.4 inter-as routing: BGP 5.5 The SDN control 5.6 ICMP: The Internet Control Message

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

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

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. 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 IV: Network Layer

Chapter IV: Network Layer Chapter IV: Network Laer UG3 Computer Communications & Networks (COMN) Mungjin Lee mungjin.lee@ed.ac.uk Slides copright of Kurose and Ross IP addresses: how to get one? Q: How does a host get IP address?

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

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

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

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

Last time. Network layer. Introduction. Virtual circuit vs. datagram details. IP: the Internet Protocol. forwarding vs. routing

Last time. Network layer. Introduction. Virtual circuit vs. datagram details. IP: the Internet Protocol. forwarding vs. routing Last time Network layer Introduction forwarding vs. routing Virtual circuit vs. datagram details connection setup, teardown VC# switching forwarding tables, longest prefix matching IP: the Internet Protocol

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

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

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: 3-bit address space soon to be completel allocated. Additional motivation: Header format helps speed processing/forwarding Header changes to facilitate QoS (service classes) Reduction

More information

HY 335 Φροντιστήριο 8 ο

HY 335 Φροντιστήριο 8 ο HY 335 Φροντιστήριο 8 ο Χειμερινό Εξάμηνο 2009-2010 Παπακωνσταντίνου Άρτεμις artpap@csd.uoc.gr 4/12/2009 Roadmap IP: The Internet Protocol IPv4 Addressing Datagram Format Transporting a datagram from source

More information

EECS 3214: Computer Networks Protocols and Applications

EECS 3214: Computer Networks Protocols and Applications EECS 3214: Computer Networks Protocols and Applications Suprakash Datta datta@cse.yorku.ca Office: CSEB 3043 Phone: 416-736-2100 ext 77875 Course page: http://www.cse.yorku.ca/course/3214 These slides

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. introduction 4. irtual circuit and datagram networks 4. what s inside a router 4.4 IP: Internet Protocol datagram format IP4 addressing ICMP IP6 4.5 routing algorithms link state

More information

Network layer. Key Network-Layer Functions. Network service model. Interplay between routing and forwarding. CSE 4213: Computer Networks II

Network layer. Key Network-Layer Functions. Network service model. Interplay between routing and forwarding. CSE 4213: Computer Networks II Chapter 4: Network Layer CSE 43: Computer Networks II Suprakash Datta datta@cs.yorku.ca Office: CSEB 3043 Phone: 46-736-00 ext 77875 Course page: http://www.cs.yorku.ca/course/43 Chapter goals: understand

More information

Lecture 4 The Network Layer. Antonio Cianfrani DIET Department Networking Group netlab.uniroma1.it

Lecture 4 The Network Layer. Antonio Cianfrani DIET Department Networking Group netlab.uniroma1.it Lecture 4 The Network Layer Antonio Cianfrani DIET Department Networking Group netlab.uniroma1.it Network layer functions Transport packet from sending to receiving hosts Network layer protocols in every

More information

Lecture 5 The Network Layer part II. Antonio Cianfrani DIET Department Networking Group netlab.uniroma1.it

Lecture 5 The Network Layer part II. Antonio Cianfrani DIET Department Networking Group netlab.uniroma1.it Lecture 5 The Network Layer part II Antonio Cianfrani DIET Department Networking Group netlab.uniroma1.it IP datagram format IP protocol version number header length (bytes) type of data max number remaining

More information

Shortest Paths Algorithms and the Internet: The Distributed Bellman Ford Lecturer: Prof. Chiara Petrioli

Shortest Paths Algorithms and the Internet: The Distributed Bellman Ford Lecturer: Prof. Chiara Petrioli Shortest Paths Algorithms and the Internet: The Distributed Bellman Ford Lecturer: Prof. Chiara Petrioli Dipartimento di Informatica Rome University La Sapienza G205: Fundamentals of Computer Engineering

More information

Network Layer. CMPS 4750/6750: Computer Networks

Network Layer. CMPS 4750/6750: Computer Networks Network Layer CMPS 4750/6750: Computer Networks 1 Outline Overview of network layer Forwarding (data plane) Routing (control plane) The Internet Protocol (IP) Routing in the Internet: OSPF, BGP 2 Network

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

Routing Algorithm Classification. A Link-State Routing Algorithm

Routing Algorithm Classification. A Link-State Routing Algorithm Routing Algorithm lassification Global or decentralied information? Global: All routers have complete topolog, link cost info Link state algorithms Decentralied: Router knows phsicallconnected neighbors,

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

Agenda. distance-vector (what you invented last Friday) hierarchical routing routing in the Internet. v DNS assignment Q&A v Routing Algorithms

Agenda. distance-vector (what you invented last Friday) hierarchical routing routing in the Internet. v DNS assignment Q&A v Routing Algorithms Agenda v DNS assignment Q&A v Routing Algorithms distance-vector (what ou invented last Frida) hierarchical routing routing in the Internet Network Laer 4- Chapter 4 Network Laer A note on the use of these

More information

BGP. Daniel Zappala. CS 460 Computer Networking Brigham Young University

BGP. Daniel Zappala. CS 460 Computer Networking Brigham Young University Daniel Zappala CS 460 Computer Networking Brigham Young University 2/20 Scaling Routing for the Internet scale 200 million destinations - can t store all destinations or all prefixes in routing tables

More information

NETWORK LAYER CONTROL PLANE

NETWORK LAYER CONTROL PLANE NETWORK LAYER CONTROL PLANE 1 GOALS Understand principles behind network control plane Traditional routing algorithms SDN controlllers Internet Control Message Protocol Network management And their instantiation,

More information