internetworking lecture # 2 hassan shuja 02/21/2006

InternetworkingInternetworking

Lecture # 2Hassan Shuja02/21/2006

Networking ProtocolsNetworking Protocols Networking ProtocolsNetworking Protocols

– Vendors developed their own networking protocolsVendors developed their own networking protocols• SNA – IBMSNA – IBM• DECnet – DEC MinicomputersDECnet – DEC Minicomputers• Apple – AppletalkApple – Appletalk

– International Organization for Standardization (ISO) International Organization for Standardization (ISO) takes on the task to develop a standardtakes on the task to develop a standard

• Open System Interconnection (OSI) developedOpen System Interconnection (OSI) developed– U.S Department of Defense (DoD) begins to U.S Department of Defense (DoD) begins to

develop networking protocoldevelop networking protocol• TCP/IPTCP/IP

Networking ProtocolsNetworking Protocols Networking protocolsNetworking protocols

– OSI suffers because of slow formal standardization OSI suffers because of slow formal standardization process never succeeds in the marketplaceprocess never succeeds in the marketplace

• TCP used by US governmentTCP used by US government

– TCP/IP takes off and becomes the most widely used TCP/IP takes off and becomes the most widely used networking protocolnetworking protocol

TCPTCP TCP Protocol StackTCP Protocol Stack

Physical

Data-Link

Internet

Transport

Application

TelnetSMTPFTP

SNMPWWWTCP

UDP

TCPTCP TCP PortsTCP Ports

Client Server

SP DP

SP DP1

2

1034

103423

23

Network DevicesNetwork Devices HubHub

– A layer 2 device that is used to connect network A layer 2 device that is used to connect network devicesdevices

– When a packet is sent from one port, it is copied to When a packet is sent from one port, it is copied to all other portsall other ports

SwitchSwitch– A layer 2 device that is used to connect network A layer 2 device that is used to connect network

devicesdevices– When a packet is sent from one port, it is directly When a packet is sent from one port, it is directly

switched to the destination portswitched to the destination port

Network DevicesNetwork Devices RouterRouter

– A layer 3 device that forwards packets across A layer 3 device that forwards packets across broadcast networksbroadcast networks

FirewallFirewall– A system designed to protect a computer network A system designed to protect a computer network

from unauthorized accessfrom unauthorized access

Packet RoutingPacket Routing Address Resolution Protocol (ARP)Address Resolution Protocol (ARP)

– Data traffic is routed using the network addressesData traffic is routed using the network addresses– Data traffic is forwarded over a physical network Data traffic is forwarded over a physical network

using MAC addressesusing MAC addresses– ARP is a method used in TCP/IP suite to map ARP is a method used in TCP/IP suite to map

network addresses to MAC addressesnetwork addresses to MAC addresses

Packet RoutingPacket Routing Address Resolution Protocol (ARP)Address Resolution Protocol (ARP)

Source IP - 10.1.1.5Destination IP - 10.1.2.5

Source MAC - 15Destination MAC - 17

IP - 10.1.1.5MAC - 15

10.1.2.5MAC - 19

IP - 10.1.1.2MAC - 16

IP - 10.1.1.1MAC - 17

IP - 10.1.2.2MAC - 18







Router#sh arp Protocol Address Age (min) Hardware Addr Type Interface Internet 155.104.78.189 0 0030.6e0a.8708 ARPA Vlan79 Internet 155.104.214.37 0 0020.4a72.19fa ARPA Vlan214 Internet 155.104.79.188 0 0020.358d.d5f6 ARPA Vlan79 Internet 155.104.77.190 0 0010.83ff.46e1 ARPA Vlan79 Internet 155.104.184.75 0 000d.6009.4b09 ARPA Vlan48 Internet 155.104.185.74 1 000c.7653.8bb7 ARPA Vlan48 Internet 155.104.211.32 1 000d.603c.06da ARPA Vlan214 Internet 155.104.41.218 2 000d.603c.b475 ARPA Vlan234 Internet 155.104.173.94 2 0009.6b32.f7b9 ARPA Vlan204 Internet 155.104.128.115 2 00d0.59ce.18fe ARPA Vlan214

Local Area Network (LAN)Local Area Network (LAN) Various LANsVarious LANs

– A high-speed network that is bounded by a small geographic area

• Tends to encompass one broadcast domain• Usually restricted to a building or floor• Operates at the layer 1 and 2 of the OSI model• Interconnected using a hub or switch

Local Area Network (LAN)Local Area Network (LAN) Various LANsVarious LANs

– Ethernet Technologies • Ethernet

• Most commonly used• Duplex – full/half• Speed – 10/100/auto

• FDDI• Token Ring

Local Area Network (LAN)Local Area Network (LAN) Transmission MethodsTransmission Methods

– UnicastUnicast• Single packet from source to destinationSingle packet from source to destination

– MulticastMulticast• Single packet that is sent to a specific subset of Single packet that is sent to a specific subset of

nodesnodes

– BroadcastBroadcast• Single packet that is sent to all nodesSingle packet that is sent to all nodes

internetworking lecture # 2 hassan shuja 02/21/2006

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