november 29, 2004 prof. paul lin 1 cpet 355 16. internetworking, addressing, and routing paul i-hai...
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November 29, 2004November 29, 2004 Prof. Paul LinProf. Paul Lin 11
CPET 355 CPET 355
16. 16.
Internetworking, Addressing, and Internetworking, Addressing, and RoutingRouting
Paul I-Hai Lin, Professor Paul I-Hai Lin, Professor Electrical and Computer Engineering TechnologyElectrical and Computer Engineering Technology
Purdue University, Fort Wayne CampusPurdue University, Fort Wayne Campus
November 29, 2004November 29, 2004 Prof. Paul LinProf. Paul Lin 22
Network Layer - an OverviewNetwork Layer - an Overview
Getting data packets from the source Getting data packets from the source all the way to the destinationall the way to the destination
Dealing with end-to-end transmissionDealing with end-to-end transmission Need to knowNeed to know
• Topology of the communication subnet Topology of the communication subnet (routers)(routers)
• Chose paths (routing algorithms)Chose paths (routing algorithms)
November 29, 2004November 29, 2004 Prof. Paul LinProf. Paul Lin 33
Position of Network LayerPosition of Network Layer
Courtesy - From Fig. 1, Page 467, Data Communications and Networks, 3rd edition, Forouzan, McGrawHill
November 29, 2004November 29, 2004 Prof. Paul LinProf. Paul Lin 44
Network Layer DutiesNetwork Layer Duties
Courtesy - From Fig. 2, Page 468, Data Communications and Networks, 3rd edition, Forouzan, McGrawHill
November 29, 2004November 29, 2004 Prof. Paul LinProf. Paul Lin 55
Network LayerNetwork LayerTopics of DiscussionTopics of Discussion
Network Layer Design IssueNetwork Layer Design Issue• Services to the TCP LayerServices to the TCP Layer
Connectionless Services (Datagram)Connectionless Services (Datagram) Connection-Oriented Services (Virtual Connection-Oriented Services (Virtual
Circuit)Circuit)
• SubnetsSubnets Internetworking Internetworking AddressingAddressing RoutingRouting
November 29, 2004November 29, 2004 Prof. Paul LinProf. Paul Lin 66
InternetworksInternetworks
Courtesy - From Fig. 19.1, Page 471, Data Communications and Networks, 3rd edition, Forouzan, McGrawHill
Host A -> Host D• 4 LANS, 1 WAN• S1, S2, S3: Switch or Router• f1, f2: Interface• Three links: S1 -> S2 -> s3
November 29, 2004November 29, 2004 Prof. Paul LinProf. Paul Lin 77
Links in an InternetworkLinks in an Internetwork
Courtesy - From Fig. 19.2, Page 472, Data Communications and Networks, 3rd edition, Forouzan, McGrawHill
November 29, 2004November 29, 2004 Prof. Paul LinProf. Paul Lin 88
Network Layer in an InternetworkNetwork Layer in an Internetwork
Courtesy - From Fig. 19.3 Page 473, Data Communications and Networks, 3rd edition, Forouzan, McGrawHill
November 29, 2004November 29, 2004 Prof. Paul LinProf. Paul Lin 99
Network Layer at the SourceNetwork Layer at the Source
Courtesy - From Fig. 19.4 Page 473, Data Communications and Networks, 3rd edition, Forouzan, McGrawHill
• Creating Source and Destination Address, Fragmentation
November 29, 2004November 29, 2004 Prof. Paul LinProf. Paul Lin 1010
Network Layer at Router or SwitchNetwork Layer at Router or Switch
Courtesy - From Fig. 19.5 Page 474, Data Communications and Networks, 3rd edition, Forouzan, McGrawHill
• Routing Table, Fragmentation
November 29, 2004November 29, 2004 Prof. Paul LinProf. Paul Lin 1111
Network Layer at DestinationNetwork Layer at Destination
Courtesy - From Fig. 196 Page 475, Data Communications and Networks, 3rd edition, Forouzan, McGrawHill
• Corrupted packet, Fragments
November 29, 2004November 29, 2004 Prof. Paul LinProf. Paul Lin 1212
Quality of ServiceQuality of ServiceRequirementsRequirements
From Fig. 5-30, Page 397, Computer Networks, 4th edition, Andrew S. Tanenbaum, Prentice Hall
November 29, 2004November 29, 2004 Prof. Paul LinProf. Paul Lin 1313
Packet-Switched Network - InternetPacket-Switched Network - Internet
Courtesy - From Fig. 196 Page 475, Data Communications and Networks, 3rd edition, Forouzan, McGrawHill
• Packets – Variable Length Data Blocks; Node to Node Delivery
• Virtual Circuit – WAN, Frame Relaying, ATM applications, call setup a single route
November 29, 2004November 29, 2004 Prof. Paul LinProf. Paul Lin 1414
Packet-Switched Network - InternetPacket-Switched Network - Internet
Courtesy - From Fig. 196 Page 475, Data Communications and Networks, 3rd edition, Forouzan, McGrawHill
• Datagram Approach – no fixed path, routing, out of order
• Packets == Datagrams
November 29, 2004November 29, 2004 Prof. Paul LinProf. Paul Lin 1515
AddressingAddressing Internet Address – IP Address
• Classful addressing – original architecture Class A, B, C, D, and E
• Classless addressing – mid 1990s IPv4
• 32-bit binary number• Dotted-Decimal Notation 128.11.3.31 255.255.255.0
IPv6 - 128-bit
November 29, 2004November 29, 2004 Prof. Paul LinProf. Paul Lin 1616
Addressing – IPV4Addressing – IPV4
Courtesy - From Fig. 19.10 Page 479, Data Communications and Networks, 3rd edition, Forouzan, McGrawHill
• Network ID, Host ID
• Class A – 128 blocks (First Byte), 16,777,216 hosts
• Class B – 16,384 blocks (First & Second Byte), 65536 hosts
• Class C – 2,097,152 blocks (First, Second, Third byte), 256 hosts
• Class D – 1 block, Multicasting
November 29, 2004November 29, 2004 Prof. Paul LinProf. Paul Lin 1717
Finding the ClassFinding the Class
Courtesy - From Fig. 19.12 Page 480, Data Communications and Networks, 3rd edition, Forouzan, McGrawHill
November 29, 2004November 29, 2004 Prof. Paul LinProf. Paul Lin 1818
Netid and HostidNetid and Hostid
Courtesy - From Fig. 19.13 Page 481, Data Communications and Networks, 3rd edition, Forouzan, McGrawHill
November 29, 2004November 29, 2004 Prof. Paul LinProf. Paul Lin 1919
Classes and Blocks - Netid 73Classes and Blocks - Netid 73
Courtesy - From Fig. 19.14 Page 482, Data Communications and Networks, 3rd edition, Forouzan, McGrawHill
128 Blocks; 16,777,216 Hosts
November 29, 2004November 29, 2004 Prof. Paul LinProf. Paul Lin 2020
Blocks in Class B NetworkBlocks in Class B Network
Courtesy - From Fig. 19.15 Page 483, Data Communications and Networks, 3rd edition, Forouzan, McGrawHill
16384 Blocks; 65536 Hosts
November 29, 2004November 29, 2004 Prof. Paul LinProf. Paul Lin 2121
Blocks in Class C NetworkBlocks in Class C Network
Courtesy - From Fig. 19.16 Page 484, Data Communications and Networks, 3rd edition, Forouzan, McGrawHill
2,097,152 Blocks; 255 Hosts
November 29, 2004November 29, 2004 Prof. Paul LinProf. Paul Lin 2222
Network AddressNetwork Address
Courtesy - From Fig. 19.17 Page 484, Data Communications and Networks, 3rd edition, Forouzan, McGrawHill
• An address defines a network with all host-id = 0
November 29, 2004November 29, 2004 Prof. Paul LinProf. Paul Lin 2323
Sample InternetSample Internet
Courtesy - From Fig. 19.18 Page 486, Data Communications and Networks, 3rd edition, Forouzan, McGrawHill
November 29, 2004November 29, 2004 Prof. Paul LinProf. Paul Lin 2424
SubnettingSubnetting
Courtesy - From Fig. 19.19 Page 487, Data Communications and Networks, 3rd edition, Forouzan, McGrawHill
• Class B – 1 block, 65536 hosts (16-bit)
• Subnets
• 2 sub-blocks (1-bit), 36768 hosts (15-bit)
• 4 sub-blocks (2-bit), 18384 hosts (14-bit)
• …
• 128 sub-blocks (7-bit), 512 host (9-bit)
November 29, 2004November 29, 2004 Prof. Paul LinProf. Paul Lin 2525
Subnetting – 3 Level HierarchySubnetting – 3 Level Hierarchy
Courtesy - From Fig. 19.20 Page 487, Data Communications and Networks, 3rd edition, Forouzan, McGrawHill
• Three levels: Site, Subnet, Host
November 29, 2004November 29, 2004 Prof. Paul LinProf. Paul Lin 2626
A Network With and Without SubnettingA Network With and Without Subnetting
Courtesy - From Fig. 19.21 Page 488, Data Communications and Networks, 3rd edition, Forouzan, McGrawHill
November 29, 2004November 29, 2004 Prof. Paul LinProf. Paul Lin 2727
MasksMasks
Courtesy - From Table 19.1 Page 489, Data Communications and Networks, 3rd edition, Forouzan, McGrawHill
ClassClass In BinaryIn BinaryIn Dotted-In Dotted-DecimalDecimal
Using SlashUsing Slash
AA 11111111 00000000 00000000 0000000011111111 00000000 00000000 00000000 255.0.0.0255.0.0.0 /8/8
BB 11111111 11111111 00000000 0000000011111111 11111111 00000000 00000000 255.255.0.0255.255.0.0 /16/16
CC 11111111 111111111 11111111 0000000011111111 111111111 11111111 00000000 255.255.255.0255.255.255.0 /24/24
November 29, 2004November 29, 2004 Prof. Paul LinProf. Paul Lin 2828
SupernettingSupernetting An organization can combine several
class C block to form a larger range of addresses
November 29, 2004November 29, 2004 Prof. Paul LinProf. Paul Lin 2929
Classless AddressingClassless Addressing Variable-Length Block (2, 4, 128, etc) Mask Finding the Network Address Subnetting CIDR (Classes InterDomain Routing)
November 29, 2004November 29, 2004 Prof. Paul LinProf. Paul Lin 3030
Dynamic Address ConfigurationDynamic Address Configuration DHCP (Dynamic Host Configuration
Protocol)• Database 1 (static) - Physical addresses to
IP addresses• Database 2 (dynamic) – Available IP, Lease
Time
November 29, 2004November 29, 2004 Prof. Paul LinProf. Paul Lin 3131
Network Address TranslationNetwork Address Translation
Courtesy – Table 19.2 Page 494, Data Communications and Networks, 3rd edition, Forouzan, McGrawHill
RangeRange TotalTotal
10.0.0.0 10.0.0.0 to to 10.255.255.255 10.255.255.255 222424
172.16.0.0 172.16.0.0 toto 172.31.255.255 172.31.255.255 222020
192.168.0.0 192.168.0.0 toto 192.168.255.255 192.168.255.255 221616
• Internally, a large set of addresses
• Externally, one address, or a small set of addresses
November 29, 2004November 29, 2004 Prof. Paul LinProf. Paul Lin 3232
A NAT ExampleA NAT Example
Courtesy – Fig 19.25 Page 495, Data Communications and Networks, 3rd edition, Forouzan, McGrawHill
• Private address: 172.18.0.0 to 172.18.255.255
• NAT Router address: 200.24.5.8
November 29, 2004November 29, 2004 Prof. Paul LinProf. Paul Lin 3333
Address TranslationAddress Translation
Courtesy – Fig. 19.25 Page 495, Data Communications and Networks, 3rd edition, Forouzan, McGrawHill
• Private address: 172.18.0.0 to 172.18.255.255
• NAT Router address: 200.24.5.8
November 29, 2004November 29, 2004 Prof. Paul LinProf. Paul Lin 3434
Address Translation (cont.)Address Translation (cont.)
Courtesy – Fig. 19.25 Page 495, Data Communications and Networks, 3rd edition, Forouzan, McGrawHill
November 29, 2004November 29, 2004 Prof. Paul LinProf. Paul Lin 3535
Translation TableTranslation Table
Courtesy – Table 19.3 Page 497, Data Communications and Networks, 3rd edition, Forouzan, McGrawHill
Private Private AddressAddress
Private Private PortPort
ExternalExternalAddressAddress
External External PortPort
TransportTransportProtocolProtocol
172.18.3.1172.18.3.1 14001400 25.8.3.225.8.3.2 8080 TCPTCP
172.18.3.2172.18.3.2 14011401 25.8.3.225.8.3.2 8080 TCPTCP
...... ...... ...... ...... ......
November 29, 2004November 29, 2004 Prof. Paul LinProf. Paul Lin 3636
Routing TechniquesRouting Techniques Routing Tables Next-Hop Routing Network-Specific Routing Host-Specific Routing Default Routing
November 29, 2004November 29, 2004 Prof. Paul LinProf. Paul Lin 3737
Translation TableTranslation Table
Courtesy – Fig. 19.27 Page 496, Data Communications and Networks, 3rd edition, Forouzan, McGrawHill
November 29, 2004November 29, 2004 Prof. Paul LinProf. Paul Lin 3838
Next-Hop RoutingNext-Hop Routing
Courtesy – Fig. 19.28 Page 498, Data Communications and Networks, 3rd edition, Forouzan, McGrawHill
November 29, 2004November 29, 2004 Prof. Paul LinProf. Paul Lin 3939
Network-Specific RoutingNetwork-Specific Routing
Courtesy – Fig. 19.29 Page 498, Data Communications and Networks, 3rd edition, Forouzan, McGrawHill
November 29, 2004November 29, 2004 Prof. Paul LinProf. Paul Lin 4040
Host-Specific RoutingHost-Specific Routing
Courtesy – Fig. 19.30 Page 499, Data Communications and Networks, 3rd edition, Forouzan, McGrawHill
November 29, 2004November 29, 2004 Prof. Paul LinProf. Paul Lin 4141
Default RoutingDefault Routing
Courtesy – Fig. 19.31 Page 500, Data Communications and Networks, 3rd edition, Forouzan, McGrawHill
November 29, 2004November 29, 2004 Prof. Paul LinProf. Paul Lin 4242
More on Routing More on Routing Static vs Dynamic
• Static Routing Table• Dynamic Routing Table and Protocols
RIP – Routing Information Protocol OSPF – Open Shortest Path First BGF – Border Gateway Protocol
Routing Tables• For Classful Addressing• For Classless Addressing (CIDR)