Link State Routing. Link State Packets. Link State Protocol. Link State Protocols Basic ideas Problems and pitfalls

Size: px
Start display at page:

Download "Link State Routing. Link State Packets. Link State Protocol. Link State Protocols Basic ideas Problems and pitfalls"

Transcription

1 Link State Routing In particular OSPF dr. C. P. J. Koymans Informatics Institute University of Amsterdam (version 1.2, 2010/03/02 13:33:33) Monday, March 1, 2010 Link State Protocols Basic ideas Problems and pitfalls OSPF Rationale Parameters Databases Network representation and architecture OSPF packet details OSPF packet header The different kinds of OSPF packets Link State Advertisement packets Link State Advertisement header The different kinds of Link State Advertisements Link State Protocol Link State Packets A Link State Protocol Builds on complete information about the network topology Uses Dijkstra s Shortest Path Tree algorithm Replaces a distance vector protocol in the case of more complex topologies Has a faster convergence time than distance vector protocols Links State Packets (LSPs) represent the state of a router and its links to the rest of the network This representation suffices for point to point links Broadcast networks (LANs) and NBMA networks are represented by virtual nodes inside the topology Designated routers (DRs) speak on their behalf

2 Non-broadcast networks Learn to know your neighbours NBMA Non-Broadcast Multiple Access Full mesh of connectivity Connectivity via elected DR Point-to-Multipoint A subset of the collection of all point-to-point links No full mesh of connectivity No DR is elected Easy on point to point links Just send out greetings (hello packets) Both ends will become adjacent A little more advanced on broadcast networks Send out hellos using multicast Not all neighbours will become adjacent LSP generation LSP distribution Periodic announcements with a long period (like 30 minutes) Triggered updates when there are changes, which can be Detection of a new neighbour (link or node coming up) Detection of a link or node failure Change of a link cost LSPs are distributed throughout the network Distribution can t use the routing database for distant nodes Why? What is the difference with RIP here? Ordinary flooding is problematic It would need a TTL to prevent loops It could cause exponential multiplication of packets Smart flooding recognizes identical LSPs Causing propagation to be tree-like

3 Most recent LSP problem Pitfalls LSPs may arrive out of order Therefore we need a mechanism to recognize older packets What about using timestamps? Timestamps cause trouble if clocks are not synchronised or out of order! What about using sequence numbers? Sequence numbers need an aging procedure to protect from stale information, for instance when a router reboots and starts from scratch Sequence numbers may wrap Sequence number ordering is not a total ordering, not even a partial ordering a < b < c < d < a Intermezzo ARPANET lockup The devilish dice There are three dice, A, B and C such that A is better than B B is better than C C is better than A A: B: C: S xcba P cba cba cba cba Q cba cba R

4 Lockup solution OSPF advantages (1) One could use a very large sequence number space and wait for timeouts after overflow One could use an age (or ttl) field and always increase the age (decrease the ttl) by at least one and furthermore increase (decrease) it periodically OSPF Introduces hierarchical routing Supports load balancing Supports subnets Supports unnumbered interfaces/networks Supports point-to-point, broadcast, NBMA and point-to-multipoint networks Supports virtual links for backbone connectivity OSPF advantages (2) OSPF fun :) OSPF Has built in authentication Uses efficient multicast for flooding Uses metrics built on cost, per interface Is easily extendable for multicast routing (MOSPF) IETF T-shirt IS IS = 0 Old time IETF versus ISO controversy But OSPF in fact really builds on BBN s research on SPF Early versions of OSI s IS-IS

5 Some OSPF facts Timers and Overflow OSPF builds directly upon IP OSPF uses protocol type 89 Current OSPF version is 2 RFC 2328 (Moy, 1998) RFC 2740 (OSPF for IPv6) version 3 OSPF uses LSA (Link State Advertisement) terminology in stead of LSP (Link State Packet) These must be the same for all OSPF neighbours HelloInterval (default 10 sec) RouterDeadInterval (default 40 sec) In case of database overflow external routing information is dropped first Consistent LSA Databases (Backup) Designated Router LSA s must be acknowledged LSA s (and their acks) are queued/flagged for transmission LSA s must time out at about the same time by using triggered distribution of age MaxAge packets which must be honored but only if there is already an LSA for this node in the local database A Designated Router (DR) and a Backup Designated Router (BDR) is elected on every multi-access network using Hello packets The (B)DR represents the network as a (virtual) node and acts on its behalf The DR/BDR election process is sticky The priority of routers can be configured

6 Multicast usage Hierarchical routing On LANs every router becomes adjacent to the Designated Router Backbone is area 0 Limbs (non-backbone) are areas not equal to 0 R Update DR Acknowledgement Update S ABRs Backbone (area 0) Multicast to AllDRouters ( ) Multicast to AllSPFRouters ( ) Virtual Links Inter Area Summaries Area 5 is not physically connected to the backbone A virtual link extends the backbone to the new ABR and behaves as an unnumbered point to point link ABRs Backbone (area 0) IASs are injected by ABRs IASs make use of a hub and spoke topology Summary information is spread RIP -like There are no loops or slow convergence Virtual links maintain the hub and spoke topology These virtual spokes are in fact paths through their transit area treated as unnumbered links in the backbone

7 Router roles Area Border Router (ABR) Backbone router Has at least one interface inside area 0 Internal router All interfaces are completely within a single area Area Border Router (ABR) Has an interface inside area 0 and one or more other areas Autonomous System Boundary Router (ASBR) Participates in another (external) routing protocol Attaches to multiple areas Runs multiple copies of the basic algorithm, once for each area Summarizes area data (destination networks) towards the backbone Receives summarized data from the backbone about other areas including the backbone itself Can aggregate summary data Autonomous System Boundary Router (ASBR) Stub(by) area Can be part of any area Interfaces with other routing protocols BGP, RIP, IS-IS,... Injects external routes into OSPF ASBR notion is independent of backbone, internal or ABR router A stub(by) area is an area into which no external routing information is injected by the ABRs It uses a default route for all external destinations A default route is injected by all ABRs A totally stubby area is a stubby area into which not even inter-area summaries are injected

8 OSPF packet header (24 bytes) OSPF packet header fields Version Type Packet length Router ID Area ID Checksum AuType Authentication OSPF packet header fields Version 2 Type 1 5 (see next slide) Packet length Total length, including this header Router ID ID of packet originating router Area ID The area a packet belongs to Checksum One s complement checksum AuType Null, Simple or Crypto Authentication Pointer to message digest (Crypto) OSPF packet types OSPF Hello packet (20 + N 4 bytes) OSPF packet types Type Meaning 1 Hello 2 Database Description 3 Link State Request 4 Link State Update 5 Link State Acknowledgement Network Mask HelloInterval Options Rtr Pri RouterDeadInterval Designated Router Backup Designated Router Neighbor #1. Neighbor #N Repeated for each living neighbor

9 OSPF Hello packet fields OSPF DD packet (2 + N 20 bytes) Hello fields Network Mask HelloInterval Options Rtr Pri RouterDeadInterval Designated Router Backup Designated Router Neighbor subnet mask of link interval in seconds between hellos multiple metrics (T 1 ); no stub area (E) router priority, used for DR election interval to consider a silent neighbor dead IP address of designated router IP address of backup designated router (living) neighbor IDs Interface MTU Options I M M S DD sequence number LSA header #1. LSA header #N Partial list of database 1 deprecated because of lack of experience with TOS OSPF DD packet fields OSPF LS request packet (N 12 bytes) DD fields Interface MTU Detection of MTU mismatch Options Same as for Hello packets I Init bit (first packet) M More bit (more packets follow) MS Master/Slave bit DD sequence number Used for ordering DD packets LSA header Link state database instance identity LS type Link State ID Advertising Router Multiple occurrences 2 Including age and sequence number

10 OSPF LS request packet fields OSPF LS Update packet LS request fields LS type Link State ID Advertising Router Link type of the LSA ID of (link type specific part of) the LSA Router ID of originating router 0 31 # LSA s (N) LSA #1 N occurrences Together these entries uniquely identify an LSA, but not an LSA instance. The Database Description packets refer to a specific LSA instance, but without actual data. LSA #N OSPF LS Update packet fields OSPF LS Acknowledgement packet (N 20 bytes) LS Update fields # LSA s Number of LSA s inside the update packet LSA #i A complete Link State Advertisement 0 31 LSA header #1 N occurrences Link State Updates contain complete and specific instances of Link State Advertisements with all relevant data. LSA header #N

11 OSPF LS Acknowledgement packet fields Link State Advertisements LS Acknowledgement fields LSA header #i A complete Link State Header Link State Acknowledgements again refer to specific instances, but contain no actual data. Multiple LSA s may be found inside a Link State Update packet Every LSA consists of LSA Header (20 bytes) LSA type specific content LSA header (20 bytes) LSA header fields LS age Options LS type Link State ID Advertising Router LS sequence number LS Checksum Length LSA header fields LS age Options LS type Link State ID Advertising Router LS sequence number LS Checksum Length Time in seconds since the LSA was originated Same as for Hello packets Link type of the LSA (see next slide) ID of (link type specific) part of the LSA Router ID of originating router Used for most recent check of LSA packets The Fletcher checksum of the LSA (without age) Length in bytes of the LSA, including the header

12 LS types NSSA LS Types Type Meaning 1 Router LSA 2 Network LSA 3 Network Summary LSA 4 AS Boundary Router Summary LSA 5 AS External LSA 7 NSSA LSA (see next slide) NSSA stands for Not So Stubby Area Support for certain external routes throughout the area itself NSSA uses its own special type (7) These LSA s are translated at the ABR into ordinary external LSA s (type 5) for the rest of the OSPF domain It is common to inject a type 7 default route from the NSSA border router(s) into the NSSA. Link State IDs Router LSA (LS type = 1) without header Link State IDs Type Meaning 1 ID of originating router 2 IP address of the network s DR 3 The destination s IP network address 4 ID of described ASBR 5 The destination s IP network address repeated # links times V E B 0 # links Link ID Link Data Type # TOS metric } TOS 0 TOS metric # TOS times 3 Originated by every router Flooded throughout the area(s) 3 For backward compatibility

13 Router LSA fields Router LSA type field Router LSA fields V Router is virtual link endpoint E Router is AS Boundary Router B Router is Area Border Router # links Number of router links described Link ID ID of the connected network Link Data Extra information on network Type Type of connected network # TOS Number of extra TOSs (usually 0) metric Cost of link Router LSA type field Type Meaning 1 Point-to-point link 2 Transit network 3 Stub network 4 Virtual link Router LSA Link ID field Router LSA Link Data field Router LSA Link ID field Type Meaning 1 ID of neighbor router 2 IP address of designated router 3 IP (sub)network number 4 ID of neighbor router Router LSA Link Data field Type Meaning 1 Originating router s interface IP address 2 Originating router s interface IP address 3 Connected (sub)network mask 4 Originating router s interface IP address

14 Network LSA (LS type = 2) without header (4 + N 4 bytes) Network LSA fields 0 31 Network Mask Attached Router } Repeated for each attached router Network LSA fields Network Mask Attached Router (Sub)network mask Router ID of router(s) on network Originated by Designated Router Flooded throughout the area Summary LSA (type = 3, 4) without header Summary LSA fields Network Mask 4 0 metric TOS TOS metric } for each desired TOS 5 Summary LSA fields Network Mask 6 Address mask for the advertised destination metric Cost to advertised destination Originated by Area Border Router Flooded throughout the area(s) 4 Only relevant for type 3 5 For backward compatibility 6 Only relevant for type 3

15 AS External LSA (LS type 5) without header AS External LSA fields Network Mask E 0 metric Forwarding address External Route Tag E TOS TOS metric Forwarding address External Route Tag for each desired TOS 7 AS External LSA fields Network Mask Address mask for the advertised destination E External cost is higher than internal cost metric Cost to advertised destination Forwarding address Comparable to Next Hop in RIP External Route Tag Comparable to Route Tag in RIP Originated by AS Boundary Router Flooded throughout the whole AS 7 For backward compatibility

OSPF Routing Protocol

OSPF Routing Protocol OSPF Routing Protocol Contents Introduction Network Architecture Campus Design Architecture Building Block Design Server Farm Design Core Block Design WAN Design Architecture Protocol Design Campus Design

More information

OSPF Version 2 (RFC 2328) Describes Autonomous Systems (AS) topology. Propagated by flooding: Link State Advertisements (LSAs).

OSPF Version 2 (RFC 2328) Describes Autonomous Systems (AS) topology. Propagated by flooding: Link State Advertisements (LSAs). OSPF Version 2 (RFC 2328) Interior gateway protocol (IGP). Routers maintain link-state database. Describes Autonomous Systems (AS) topology. Propagated by flooding: Link State Advertisements (LSAs). Router

More information

Route Discovery Protocols

Route Discovery Protocols Route Discovery Protocols Columbus, OH 43210 Jain@cse.ohio-State.Edu http://www.cse.ohio-state.edu/~jain/ 1 Overview Building Routing Tables Routing Information Protocol Version 1 (RIP V1) RIP V2 OSPF

More information

GregSowell.com. Mikrotik Routing

GregSowell.com. Mikrotik Routing Mikrotik Routing Static Dynamic Routing To Be Discussed RIP Quick Discussion OSPF BGP What is Routing Wikipedia has a very lengthy explanation http://en.wikipedia.org/wiki/routing In the context of this

More information

Monitoring Routing. Monitoring OSPF LSAs. Type 1 CHAPTER

Monitoring Routing. Monitoring OSPF LSAs. Type 1 CHAPTER 44 CHAPTER You can use ASDM to monitor OSPF LSAs, OSPF and EIGRP neighbors, and the routing table. To access the routing monitoring screens, go to Monitoring > Routing in the ASDM interface. This section

More information

Link-State Routing Protocols

Link-State Routing Protocols Link-State Routing Protocols Malin Bornhager Halmstad University Session Number 2002, Svenska-CNAP Halmstad University 1 Objectives Link-state routing protocol Single-area OSPF concepts Single-area OSPF

More information

Textbook Required: Cisco Networking Academy Program CCNP: Building Scalable Internetworks v5.0 Lab Manual.

Textbook Required: Cisco Networking Academy Program CCNP: Building Scalable Internetworks v5.0 Lab Manual. Course: NET 251 Building Scalable Internetworks Credits: 3 Textbook Required: Cisco Networking Academy Program CCNP: Building Scalable Internetworks v5.0 Lab Manual. Course Description: In this course,

More information

Introduction to Link State Protocols

Introduction to Link State Protocols 1 Introduction to Link State Protocols Session Scott Sturgess scsturge@cisco.com 2 Agenda Overview of Link State Protocols Concepts in Link State Protocols The Dijkstra Algorithm Link State Concepts Comparison

More information

Chapter 10 Link-State Routing Protocols

Chapter 10 Link-State Routing Protocols Chapter 10 Link-State Routing Protocols CCNA2-1 Chapter 10 Note for Instructors These presentations are the result of a collaboration among the instructors at St. Clair College in Windsor, Ontario. Thanks

More information

OSPF Configuring Multi-Area OSPF

OSPF Configuring Multi-Area OSPF OSPF Configuring Multi-Area OSPF Objective In this lab configure a multiarea OSPF operation, interarea summarization, external route summarization, and default routing. Scenario International Travel Agency

More information

Layer 3 Routing User s Manual

Layer 3 Routing User s Manual User s Manual Second Edition, July 2011 www.moxa.com/product 2011 Moxa Inc. All rights reserved. User s Manual The software described in this manual is furnished under a license agreement and may be used

More information

Using OSPF in an MPLS VPN Environment

Using OSPF in an MPLS VPN Environment Using OSPF in an MPLS VPN Environment Overview This module introduces the interaction between multi-protocol Border Gateway Protocol (MP-BGP) running between Provider Edge routers (s) and Open Shortest

More information

Introduction to TCP/IP

Introduction to TCP/IP Introduction to TCP/IP Raj Jain The Ohio State University Columbus, OH 43210 Nayna Networks Milpitas, CA 95035 Email: Jain@ACM.Org http://www.cis.ohio-state.edu/~jain/ 1 Overview! Internetworking Protocol

More information

ZXR10 5900/5200 Series

ZXR10 5900/5200 Series ZXR10 5900/5200 Series All Gigabit-Port Intelligent Routing Switch User Manual (IPv4 Routing Volume) Version 2.8.23.A ZTE CORPORATION ZTE Plaza, Keji Road South, Hi-Tech Industrial Park, Nanshan District,

More information

Interconnecting Multiple OSPF Areas

Interconnecting Multiple OSPF Areas C H A P T E R 4 Interconnecting Multiple OSPF Areas This chapter introduces readers to the use, operation, configuration, and verification of Open Shortest Path First (OSPF) in multiple areas. After completing

More information

Routing with OSPF. Introduction

Routing with OSPF. Introduction Routing with OSPF Introduction The capabilities of an internet are largely determined by its routing protocol. An internet's scalability, its ability to quickly route around failures, and the consumption

More information

Example: Advertised Distance (AD) Example: Feasible Distance (FD) Example: Successor and Feasible Successor Example: Successor and Feasible Successor

Example: Advertised Distance (AD) Example: Feasible Distance (FD) Example: Successor and Feasible Successor Example: Successor and Feasible Successor 642-902 Route: Implementing Cisco IP Routing Course Introduction Course Introduction Module 01 - Planning Routing Services Lesson: Assessing Complex Enterprise Network Requirements Cisco Enterprise Architectures

More information

Cisco CCNP 642 901 Optimizing Converged Cisco Networks (ONT)

Cisco CCNP 642 901 Optimizing Converged Cisco Networks (ONT) Cisco CCNP 642 901 Optimizing Converged Cisco Networks (ONT) Course Number: 642 901 Length: 5 Day(s) Certification Exam This course will help you prepare for the following exams: Cisco CCNP Exam 642 901:

More information

Routing Protocols OSPF CHAPTER. The following topics describe supported routing protocols. Topics include OSPF, page 9-1 IS-IS Protocol, page 9-3

Routing Protocols OSPF CHAPTER. The following topics describe supported routing protocols. Topics include OSPF, page 9-1 IS-IS Protocol, page 9-3 CHAPTER 9 The following topics describe supported routing protocols. Topics include OSPF, page 9-1 IS-IS Protocol, page 9-3 OSPF Open Shortest Path First (OSPF) is a link state Internet routing protocol.

More information

Introduction to ISIS. ISP/IXP Workshops

Introduction to ISIS. ISP/IXP Workshops Introduction to ISIS ISP/IXP Workshops 1 IS-IS Standards History ISO 10589 specifies OSI IS-IS routing protocol for CLNS traffic A Link State protocol with a 2 level hierarchical architecture Type/Length/Value

More information

Cisco s OSPF Implementation P1C-107

Cisco s OSPF Implementation P1C-107 Configuring OSPF This chapter describes how to configure OSPF. For a complete description of the OSPF commands in this chapter, refer to the OSPF s chapter of the Network Protocols Reference, Part 1. To

More information

CCNA2 Chapter 11 Practice

CCNA2 Chapter 11 Practice CCNA2 Chapter 11 Practice Two neighbouring routers are configured for OSPF, but they have different hello and dead intervals. What will happen? They will become adjacent as long as they are configured

More information

Dynamic Routing Protocols II OSPF. Distance Vector vs. Link State Routing

Dynamic Routing Protocols II OSPF. Distance Vector vs. Link State Routing Dynamic Routing Protocols II OSPF Relates to Lab 4. This module covers link state routing and the Open Shortest Path First (OSPF) routing protocol. 1 Distance Vector vs. Link State Routing With distance

More information

IP Routing Configuring RIP, OSPF, BGP, and PBR

IP Routing Configuring RIP, OSPF, BGP, and PBR 13 IP Routing Configuring RIP, OSPF, BGP, and PBR Contents Overview..................................................... 13-6 Routing Protocols.......................................... 13-6 Dynamic Routing

More information

Deploying OSPF for ISPs. OSPF Design. Agenda. Service Providers. SP Architecture. SP Architecture. OSPF Design in SP Networks

Deploying OSPF for ISPs. OSPF Design. Agenda. Service Providers. SP Architecture. SP Architecture. OSPF Design in SP Networks Agenda OSPF Design in SP Networks Deploying OSPF for ISPs Adding Networks in OSPF OSPF in IOS ISP/IXP 1 2 Service Providers OSPF Design As applicable to Service Provider Networks SP networks are divided

More information

Advanced Networking Routing: RIP, OSPF, Hierarchical routing, BGP

Advanced Networking Routing: RIP, OSPF, Hierarchical routing, BGP Advanced Networking Routing: RIP, OSPF, Hierarchical routing, BGP Renato Lo Cigno Routing Algorithms: One or Many? Is there a single routing protocol in the Internet? How can different protocols and algorithms

More information

Networking. Palo Alto Networks. PAN-OS Administrator s Guide Version 6.0. Copyright 2007-2015 Palo Alto Networks

Networking. Palo Alto Networks. PAN-OS Administrator s Guide Version 6.0. Copyright 2007-2015 Palo Alto Networks Networking Palo Alto Networks PAN-OS Administrator s Guide Version 6.0 Contact Information Corporate Headquarters: Palo Alto Networks 4401 Great America Parkway Santa Clara, CA 95054 www.paloaltonetworks.com/company/contact-us

More information

CCNP CISCO CERTIFIED NETWORK PROFESSIONAL LAB MANUAL

CCNP CISCO CERTIFIED NETWORK PROFESSIONAL LAB MANUAL CCNP CISCO CERTIFIED NETWORK PROFESSIONAL LAB MANUAL VER 2.0 Page 1 of 315 ACKNOWLEDGEMENT We can write a 1000 page book, but we can t find enough words to describe the credit Mr. Siddiq Ahmed deserves

More information

Distance Vector Routing Protocols. Routing Protocols and Concepts Ola Lundh

Distance Vector Routing Protocols. Routing Protocols and Concepts Ola Lundh Distance Vector Routing Protocols Routing Protocols and Concepts Ola Lundh Objectives The characteristics of distance vector routing protocols. The network discovery process of distance vector routing

More information

Based on Computer Networking, 4 th Edition by Kurose and Ross

Based on Computer Networking, 4 th Edition by Kurose and Ross Computer Networks Internet Routing Based on Computer Networking, 4 th Edition by Kurose and Ross Intra-AS Routing Also known as Interior Gateway Protocols (IGP) Most common Intra-AS routing protocols:

More information

Outline. Internet Routing. Alleviating the Problem. DV Algorithm. Routing Information Protocol (RIP) Link State Routing. Routing algorithms

Outline. Internet Routing. Alleviating the Problem. DV Algorithm. Routing Information Protocol (RIP) Link State Routing. Routing algorithms Outline Internet Routing Venkat Padmanabhan Microsoft Research 9 pril 2001 Routing algorithms distance-vector (DV) link-state (LS) Internet Routing border gateway protocol (BGP) BGP convergence paper Venkat

More information

DYNAMIC MULTIPOINT VPN HUB AND SPOKE INTRODUCTION

DYNAMIC MULTIPOINT VPN HUB AND SPOKE INTRODUCTION DYNAMIC MULTIPOINT VPN HUB AND SPOKE INTRODUCTION NOVEMBER 2004 1 INTRODUCTION Spoke, Presentation_ID 11/04 2004, Cisco Systems, Inc. All rights reserved. 2 What is Dynamic Multipoint VPN? Dynamic Multipoint

More information

Internet Firewall CSIS 4222. Packet Filtering. Internet Firewall. Examples. Spring 2011 CSIS 4222. net15 1. Routers can implement packet filtering

Internet Firewall CSIS 4222. Packet Filtering. Internet Firewall. Examples. Spring 2011 CSIS 4222. net15 1. Routers can implement packet filtering Internet Firewall CSIS 4222 A combination of hardware and software that isolates an organization s internal network from the Internet at large Ch 27: Internet Routing Ch 30: Packet filtering & firewalls

More information

Routing Protocols. Interconnected ASes. Hierarchical Routing. Hierarchical Routing

Routing Protocols. Interconnected ASes. Hierarchical Routing. Hierarchical Routing Routing Protocols scale: with 200 million destinations: can t store all dest s in routing tables! routing table exchange would swamp links! Hierarchical Routing Our routing study thus far - idealization

More information

Route Optimization. rek. 2005 Petr Grygarek, VSB-TU Ostrava, Routed and Switched Networks 1

Route Optimization. rek. 2005 Petr Grygarek, VSB-TU Ostrava, Routed and Switched Networks 1 Route Optimization (intra-as) Petr Grygárek rek 1 Goal of route optimization Static routing: More predictable and safer Dynamic routing: Automatically ally reacts on topology changes Lower administration

More information

Chapter 4. Distance Vector Routing Protocols

Chapter 4. Distance Vector Routing Protocols Chapter 4 Distance Vector Routing Protocols CCNA2-1 Chapter 4 Note for Instructors These presentations are the result of a collaboration among the instructors at St. Clair College in Windsor, Ontario.

More information

CCNA 2 v5.0 Routing Protocols Final Exam Answers

CCNA 2 v5.0 Routing Protocols Final Exam Answers CCNA 2 v5.0 Routing Protocols Final Exam Answers 1 Refer to the exhibit. What can be concluded about network 192.168.1.0 in the R2 routing table? This network was learned through summary LSAs from an ABR.*

More information

GregSowell.com. Intro to Networking Mikrotik/Cisco

GregSowell.com. Intro to Networking Mikrotik/Cisco Intro to Networking Mikrotik/Cisco Terms Used Layer X When I refer to something being at layer X I m referring to the OSI model. VLAN 802.1Q Layer 2 marking on traffic used to segment sets of traffic.

More information

6.263 Data Communication Networks

6.263 Data Communication Networks 6.6 Data Communication Networks Lecture : Internet Routing (some slides are taken from I. Stoica and N. Mckewon & T. Griffin) Dina Katabi dk@mit.edu www.nms.csail.mit.edu/~dina Books Text Book Data Communication

More information

ITRI CCL. IP Routing Primer. Paul C. Huang, Ph.D. ITRI / CCL / N300. CCL/N300; Paul Huang 1999/6/2 1

ITRI CCL. IP Routing Primer. Paul C. Huang, Ph.D. ITRI / CCL / N300. CCL/N300; Paul Huang 1999/6/2 1 IP Routing Primer Paul C. Huang, Ph.D. ITRI / / N300 /N300; Paul Huang 1999/6/2 1 Basic Addressing / Subnetting Class A 0 Network Host Host Host 127 networks / 16,777,216 hosts Class A natural mask 255.0.0.0

More information

CSE331: Introduction to Networks and Security. Lecture 8 Fall 2006

CSE331: Introduction to Networks and Security. Lecture 8 Fall 2006 CSE331: Introduction to Networks and Security Lecture 8 Fall 2006 Announcements Reminders: Project I is due on Monday, Sept. 25th. Homework 1 is due on Friday, Sept. 29th. CSE331 Fall 2004 2 Internet Protocol

More information

Module 7. Routing and Congestion Control. Version 2 CSE IIT, Kharagpur

Module 7. Routing and Congestion Control. Version 2 CSE IIT, Kharagpur Module 7 Routing and Congestion Control Lesson 4 Border Gateway Protocol (BGP) Specific Instructional Objectives On completion of this lesson, the students will be able to: Explain the operation of the

More information

IMPLEMENTING CISCO IP ROUTING V2.0 (ROUTE)

IMPLEMENTING CISCO IP ROUTING V2.0 (ROUTE) IMPLEMENTING CISCO IP ROUTING V2.0 (ROUTE) COURSE OVERVIEW: Implementing Cisco IP Routing (ROUTE) v2.0 is an instructor-led five day training course developed to help students prepare for Cisco CCNP _

More information

Routing Protocols (RIP, OSPF, BGP)

Routing Protocols (RIP, OSPF, BGP) Chapter 13 Routing Protocols (RIP, OSPF, BGP) INTERIOR AND EXTERIOR ROUTING RIP OSPF BGP 1 The McGraw-Hill Companies, Inc., 2000 1 Introduction Packets may pass through several networks on their way to

More information

Using the Border Gateway Protocol for Interdomain Routing

Using the Border Gateway Protocol for Interdomain Routing CHAPTER 12 Using the Border Gateway Protocol for Interdomain Routing The Border Gateway Protocol (BGP), defined in RFC 1771, provides loop-free interdomain routing between autonomous systems. (An autonomous

More information

Seminar Seite 1 von 10

Seminar Seite 1 von 10 Seminar Seite 1 von 10 CISCO - Implementing Cisco IP Routing (ROUTE) Dauer: 5 Tage Kosten: 2.490,00 EUR (pro Person / zzgl. MwSt) Ziele: Der Kurs Implementing Cisco IP Routing (ROUTE) vermittelt den Teilnehmern

More information

Integrated IS-IS Design and Deployment Guide

Integrated IS-IS Design and Deployment Guide Integrated IS-IS Design and Deployment Guide Authors: Stefano Previdi - isco Systems Paul Horrocks - isco Systems Integrated IS-IS Design and Deployment Guide 1 ontents: 1 Executive summary... 3 2. IS-IS

More information

O 10.16.1.0/27 [110/129] via 192.168.1.5, 00:00:05, Serial0/0/1

O 10.16.1.0/27 [110/129] via 192.168.1.5, 00:00:05, Serial0/0/1 1 Which two statements are true regarding the advantages of the use of static routes? (Choose increased security reduced effort in configuring routes the administrator maintains control over routing easier

More information

Computer Networks 1 (Mạng Máy Tính 1) Lectured by: Dr. Phạm Trần Vũ

Computer Networks 1 (Mạng Máy Tính 1) Lectured by: Dr. Phạm Trần Vũ Computer Networks 1 (Mạng Máy Tính 1) Lectured by: Dr. Phạm Trần Vũ 1 Lecture 7: Network Layer in the Internet Reference: Chapter 5 - Computer Networks, Andrew S. Tanenbaum, 4th Edition, Prentice Hall,

More information

Datagram-based network layer: forwarding; routing. Additional function of VCbased network layer: call setup.

Datagram-based network layer: forwarding; routing. Additional function of VCbased network layer: call setup. CEN 007C Computer Networks Fundamentals Instructor: Prof. A. Helmy Homework : Network Layer Assigned: Nov. 28 th, 2011. Due Date: Dec 8 th, 2011 (to the TA) 1. ( points) What are the 2 most important network-layer

More information

Objectives. The Role of Redundancy in a Switched Network. Layer 2 Loops. Broadcast Storms. More problems with Layer 2 loops

Objectives. The Role of Redundancy in a Switched Network. Layer 2 Loops. Broadcast Storms. More problems with Layer 2 loops ITE I Chapter 6 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 1 Objectives Implement Spanning Tree Protocols LAN Switching and Wireless Chapter 5 Explain the role of redundancy in a converged

More information

Interconnecting Cisco Networking Devices Part 2

Interconnecting Cisco Networking Devices Part 2 Interconnecting Cisco Networking Devices Part 2 Course Number: ICND2 Length: 5 Day(s) Certification Exam This course will help you prepare for the following exam: 640 816: ICND2 Course Overview This course

More information

How To Understand Bg

How To Understand Bg Table of Contents BGP Case Studies...1 BGP4 Case Studies Section 1...3 Contents...3 Introduction...3 How Does BGP Work?...3 ebgp and ibgp...3 Enabling BGP Routing...4 Forming BGP Neighbors...4 BGP and

More information

Routing in Small Networks. Internet Routing Overview. Agenda. Routing in Large Networks

Routing in Small Networks. Internet Routing Overview. Agenda. Routing in Large Networks Routing in Small Networks Internet Routing Overview AS, IGP,, BGP in small networks distance vector or link state protocols like RIP or OSPF can be used for dynamic routing it is possible that every router

More information

IPv6 Routing Protocols. OSPFv3 TLF 2008 Cisco Systems, Inc. All rights reserved. Cisco Public

IPv6 Routing Protocols. OSPFv3 TLF 2008 Cisco Systems, Inc. All rights reserved. Cisco Public IPv6 Routing Protocols 2008 Cisco Systems, Inc. All rights reserved. Cisco Public 1 IPv6 Routing Protocols As in IPv4, IPv6 has 2 families of routing protocols: IGP and EGP, and still uses the longest-prefix

More information

The Complete IS-IS Routing Protocol

The Complete IS-IS Routing Protocol Hannes Gredler and Walter Goralski The Complete IS-IS Routing Protocol 4y Springer Contents Foreword Credits and Thanks vii ix 1 Introduction, Motivation and Historical Background 1 1.1 Motivation 1 1.2

More information

Zarząd (7 osób) F inanse (13 osób) M arketing (7 osób) S przedaż (16 osób) K adry (15 osób)

Zarząd (7 osób) F inanse (13 osób) M arketing (7 osób) S przedaż (16 osób) K adry (15 osób) QUESTION NO: 8 David, your TestKing trainee, asks you about basic characteristics of switches and hubs for network connectivity. What should you tell him? A. Switches take less time to process frames than

More information

Border Gateway Protocol (BGP-4)

Border Gateway Protocol (BGP-4) Vanguard Applications Ware IP and LAN Feature Protocols Border Gateway Protocol (BGP-4) Notice 2008 Vanguard Networks 25 Forbes Blvd Foxboro, MA 02035 Phone: (508) 964 6200 Fax: (508) 543 0237 All rights

More information

Transport and Network Layer

Transport and Network Layer Transport and Network Layer 1 Introduction Responsible for moving messages from end-to-end in a network Closely tied together TCP/IP: most commonly used protocol o Used in Internet o Compatible with a

More information

IP - The Internet Protocol

IP - The Internet Protocol Orientation IP - The Internet Protocol IP (Internet Protocol) is a Network Layer Protocol. IP s current version is Version 4 (IPv4). It is specified in RFC 891. TCP UDP Transport Layer ICMP IP IGMP Network

More information

s@lm@n Juniper Exam JN0-343 Juniper Networks Certified Internet Specialist (JNCIS-ENT) Version: 10.1 [ Total Questions: 498 ]

s@lm@n Juniper Exam JN0-343 Juniper Networks Certified Internet Specialist (JNCIS-ENT) Version: 10.1 [ Total Questions: 498 ] s@lm@n Juniper Exam JN0-343 Juniper Networks Certified Internet Specialist (JNCIS-ENT) Version: 10.1 [ Total Questions: 498 ] Topic 1, Volume A Question No : 1 - (Topic 1) How much overhead does the GRE

More information

Administrative Distance

Administrative Distance RIP is a distance vector routing protocol. It shares routing information through the local broadcast in every 30 seconds. In this tutorial we will explain RIP routing fundamentals with examples such as

More information

ECSE-6600: Internet Protocols Exam 2

ECSE-6600: Internet Protocols Exam 2 ECSE-6600: Internet Protocols Exam 2 Time: 75 min (strictly enforced) Points: 50 YOUR NAME: Be brief, but DO NOT omit necessary detail {Note: Simply copying text directly from the slides or notes will

More information

EIGRP Commands. Cisco IOS IP Command Reference, Volume 2 of 3: Routing Protocols IP2R-141

EIGRP Commands. Cisco IOS IP Command Reference, Volume 2 of 3: Routing Protocols IP2R-141 EIGRP Commands Use the commands in this chapter to configure and monitor Enhanced Interior Gateway Routing Protocol (EIGRP). For EIGRP configuration information and examples, refer to the Configuring IP

More information

Exterior Gateway Protocols (BGP)

Exterior Gateway Protocols (BGP) Exterior Gateway Protocols (BGP) Internet Structure Large ISP Large ISP Stub Dial-Up ISP Small ISP Stub Stub Stub Autonomous Systems (AS) Internet is not a single network! The Internet is a collection

More information

Recovery Performance in Redundant. Campus Network

Recovery Performance in Redundant. Campus Network Technical report, IDE0960, December 2009 Recovery Performance in Redundant Campus Network Master s Thesis in Computer Systems Engineering Sergo Mchedlishvili Master s Thesis in Computer Networks Engineering

More information

KT The Value Networking Company

KT The Value Networking Company KT The Value Networking Company IRIMS (Internet Routing Information Management System) 2005. 9 Y.D. KIM, G.E.KIM, C.K.Hwang, J.H.YOO (webman, gekim, ckhwang, styoo@kt kt.co..co.kr) Abstract An AS (Autonomous

More information

640-816: Interconnecting Cisco Networking Devices Part 2 v1.1

640-816: Interconnecting Cisco Networking Devices Part 2 v1.1 640-816: Interconnecting Cisco Networking Devices Part 2 v1.1 Course Introduction Course Introduction Chapter 01 - Small Network Implementation Introducing the Review Lab Cisco IOS User Interface Functions

More information

Introduction to IP Multicast Routing

Introduction to IP Multicast Routing Introduction to IP Multicast Routing by Chuck Semeria and Tom Maufer Abstract The first part of this paper describes the benefits of multicasting, the Multicast Backbone (MBONE), Class D addressing, and

More information

Advanced IP Addressing

Advanced IP Addressing Advanced IP Addressing CS-765 A Aspects Of Systems Administration Spring-2005 Instructure: Jan Schauman Stevens Institute Of Technology, NJ. Prepared By: Modh, Jay A. M.S. NIS SID: 999-14-0352 Date: 05/02/2005

More information

Scaling. 8.1 SPF Enhancements

Scaling. 8.1 SPF Enhancements C H A P T E R 8 Scaling Scalable may well be one of the most overused words in the network designer s lexicon. It applies to protocols, to software, to operating systems, to hardware architecture, and

More information

DG Forwarding Algorithm

DG Forwarding Algorithm DG Forwarding Algorithm Host or Router first check if destination on same Network Router multiple interfaces Match found deliver to that Network If not found default router for every router a default router

More information

APNIC elearning: BGP Basics. Contact: training@apnic.net. erou03_v1.0

APNIC elearning: BGP Basics. Contact: training@apnic.net. erou03_v1.0 erou03_v1.0 APNIC elearning: BGP Basics Contact: training@apnic.net Overview What is BGP? BGP Features Path Vector Routing Protocol Peering and Transit BGP General Operation BGP Terminology BGP Attributes

More information

IP Multicasting. Applications with multiple receivers

IP Multicasting. Applications with multiple receivers IP Multicasting Relates to Lab 10. It covers IP multicasting, including multicast addressing, IGMP, and multicast routing. 1 Applications with multiple receivers Many applications transmit the same data

More information

Computer Networks. Main Functions

Computer Networks. Main Functions Computer Networks The Network Layer 1 Routing. Forwarding. Main Functions 2 Design Issues Services provided to transport layer. How to design network-layer protocols. 3 Store-and-Forward Packet Switching

More information

PRASAD ATHUKURI Sreekavitha engineering info technology,kammam

PRASAD ATHUKURI Sreekavitha engineering info technology,kammam Multiprotocol Label Switching Layer 3 Virtual Private Networks with Open ShortestPath First protocol PRASAD ATHUKURI Sreekavitha engineering info technology,kammam Abstract This paper aims at implementing

More information

Network Layer IPv4. Dr. Sanjay P. Ahuja, Ph.D. Fidelity National Financial Distinguished Professor of CIS. School of Computing, UNF

Network Layer IPv4. Dr. Sanjay P. Ahuja, Ph.D. Fidelity National Financial Distinguished Professor of CIS. School of Computing, UNF Network Layer IPv4 Dr. Sanjay P. Ahuja, Ph.D. Fidelity National Financial Distinguished Professor of CIS School of Computing, UNF IPv4 Internet Protocol (IP) is the glue that holds the Internet together.

More information

Introduction to LAN/WAN. Network Layer

Introduction to LAN/WAN. Network Layer Introduction to LAN/WAN Network Layer Topics Introduction (5-5.1) Routing (5.2) (The core) Internetworking (5.5) Congestion Control (5.3) Network Layer Design Isues Store-and-Forward Packet Switching Services

More information

Inter-domain Routing Basics. Border Gateway Protocol. Inter-domain Routing Basics. Inter-domain Routing Basics. Exterior routing protocols created to:

Inter-domain Routing Basics. Border Gateway Protocol. Inter-domain Routing Basics. Inter-domain Routing Basics. Exterior routing protocols created to: Border Gateway Protocol Exterior routing protocols created to: control the expansion of routing tables provide a structured view of the Internet by segregating routing domains into separate administrations

More information

High Availability Campus Network Design Routed Access Layer using EIGRP or OSPF

High Availability Campus Network Design Routed Access Layer using EIGRP or OSPF High Availability Campus Network Design Routed Access Layer using EIGRP or OSPF Contents Introduction 2 Audience 3 Document Objectives 3 Overview 3 Routing in the Access 5 Routing in the Campus 5 Migrating

More information

IP Routing Configuring Static Routes

IP Routing Configuring Static Routes 11 IP Routing Configuring Static Routes Contents Overview..................................................... 11-3 IP Addressing.............................................. 11-3 Networks.................................................

More information

Lecture 12: Link-state Routing"

Lecture 12: Link-state Routing Lecture 2: Link-state Routing" CSE 23: Computer Networks Alex C. Snoeren HW 3 due next Tuesday! Lecture 2 Overview" Routing overview Intra vs. Inter-domain routing Link-state routing protocols CSE 23 Lecture

More information

Owning the Routing Table New OSPF Attacks

Owning the Routing Table New OSPF Attacks Owning the Routing Table New OSPF Attacks Alex Kirshon, Dima Gonikman, Dr. Gabi Nakibly Technion, CS department Haifa, Israel Abstract Open Shortest Path First (OSPF) is the most popular interior gateway

More information

Internet Control Message Protocol (ICMP)

Internet Control Message Protocol (ICMP) SFWR 4C03: Computer Networks & Computer Security Jan 31-Feb 4, 2005 Lecturer: Kartik Krishnan Lecture 13-16 Internet Control Message Protocol (ICMP) The operation of the Internet is closely monitored by

More information

Transitioning to BGP. ISP Workshops. Last updated 24 April 2013

Transitioning to BGP. ISP Workshops. Last updated 24 April 2013 Transitioning to BGP ISP Workshops Last updated 24 April 2013 1 Scaling the network How to get out of carrying all prefixes in IGP 2 Why use BGP rather than IGP? p IGP has Limitations: n The more routing

More information

Introduction to Dynamic Routing Protocols

Introduction to Dynamic Routing Protocols CHAPTER 3 Introduction to Dynamic Routing Protocols Objectives Upon completion of this chapter, you should be able to answer the following questions: Can you describe the role of dynamic routing protocols

More information

WHITE PAPER. Understanding IP Addressing: Everything You Ever Wanted To Know

WHITE PAPER. Understanding IP Addressing: Everything You Ever Wanted To Know WHITE PAPER Understanding IP Addressing: Everything You Ever Wanted To Know Understanding IP Addressing: Everything You Ever Wanted To Know CONTENTS Internet Scaling Problems 1 Classful IP Addressing 3

More information

Understanding Virtual Router and Virtual Systems

Understanding Virtual Router and Virtual Systems Understanding Virtual Router and Virtual Systems PAN- OS 6.0 Humair Ali Professional Services Content Table of Contents VIRTUAL ROUTER... 5 CONNECTED... 8 STATIC ROUTING... 9 OSPF... 11 BGP... 17 IMPORT

More information

Border Gateway Protocol (BGP)

Border Gateway Protocol (BGP) Border Gateway Protocol (BGP) Petr Grygárek rek 1 Role of Autonomous Systems on the Internet 2 Autonomous systems Not possible to maintain complete Internet topology information on all routers big database,

More information

Internetworking and Internet-1. Global Addresses

Internetworking and Internet-1. Global Addresses Internetworking and Internet Global Addresses IP servcie model has two parts Datagram (connectionless) packet delivery model Global addressing scheme awaytoidentifyall H in the internetwork Properties

More information

IP Routing: ISIS Configuration Guide, Cisco IOS Release 12.4T

IP Routing: ISIS Configuration Guide, Cisco IOS Release 12.4T IP Routing: ISIS Configuration Guide, Cisco IOS Release 12.4T Americas Headquarters Cisco Systems, Inc. 170 West Tasman Drive San Jose, CA 95134-1706 USA http://www.cisco.com Tel: 408 526-4000 800 553-NETS

More information

VLSM and CIDR Malin Bornhager Halmstad University

VLSM and CIDR Malin Bornhager Halmstad University VLSM and CIDR Malin Bornhager Halmstad University Session Number 2002, Svenska-CNAP Halmstad University 1 Objectives Classless routing VLSM Example of a VLSM calculation 2 Classless routing CIDR (Classless

More information

Cisco Certified Network Associate Exam. Operation of IP Data Networks. LAN Switching Technologies. IP addressing (IPv4 / IPv6)

Cisco Certified Network Associate Exam. Operation of IP Data Networks. LAN Switching Technologies. IP addressing (IPv4 / IPv6) Cisco Certified Network Associate Exam Exam Number 200-120 CCNA Associated Certifications CCNA Routing and Switching Operation of IP Data Networks Operation of IP Data Networks Recognize the purpose and

More information

IP Addressing A Simplified Tutorial

IP Addressing A Simplified Tutorial Application Note IP Addressing A Simplified Tutorial July 2002 COMPAS ID 92962 Avaya Labs 1 All information in this document is subject to change without notice. Although the information is believed to

More information

CS335 Sample Questions for Exam #2

CS335 Sample Questions for Exam #2 CS335 Sample Questions for Exam #2.) Compare connection-oriented with connectionless protocols. What type of protocol is IP? How about TCP and UDP? Connection-oriented protocols Require a setup time to

More information

Evaluation And Implementation Of The Open Shortest Path First (OSPF) Routing Protocol

Evaluation And Implementation Of The Open Shortest Path First (OSPF) Routing Protocol Evaluation And Implementation Of The Open Shortest Path First (OSPF) Routing Protocol G.C NWALOZIE 1, V.N OKOROGU 2, A.C OKAFOR 3, A.O UMEH 4 1, 2, 3,4 Electronic and Computer Engineering Department, Nnamdi

More information

Security in Internet Routing Protocols

Security in Internet Routing Protocols Security in Internet Routing Protocols Niklas Alberth nikal407@student.liu.se Rickard von Essen ricvo248@student.liu.se Linköping Institute of Technology IDA Department of Computer and Information Science

More information

Computer Networks II Master degree in Computer Engineering Exam session: 11/02/2009 Teacher: Emiliano Trevisani. Student Identification number

Computer Networks II Master degree in Computer Engineering Exam session: 11/02/2009 Teacher: Emiliano Trevisani. Student Identification number Computer Networks II Master degree in Computer Engineering Exam session: 11/02/2009 Teacher: Emiliano Trevisani Last name First name Student Identification number You are only allowed to use a pen and

More information