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Computer Networks. Internetworking Devices. Network Interface Card (NIC) Repeaters HUB Bridge Switch Router. NIC. Usually PCI Card Plugs into Motherboard Separately designed for Ethernet, Token Ring, FDDI etc Communicate with network through Serial Connection
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Internetworking Devices • Network Interface Card (NIC) • Repeaters • HUB • Bridge • Switch • Router
NIC • Usually PCI Card • Plugs into Motherboard • Separately designed for Ethernet, Token Ring, FDDI etc • Communicate with network through Serial Connection • Communicate with System with Parallel Connection • Have embedded MAC/Physical Address on a chip
NIC Functionality • Performs most of Layer Two functions • LLC (Logical Link Control) • Interface with upper layers • MAC (Medium Access Control) • Shared access to medium • Framing • Packages Frames • Signaling • Create Bits/Signals for transmission over Medium • Error Detection • New NICs have built-in Error Detection Facility
Repeaters • It boosts the signal so that it could travel a longer cable length • Works at layer One (Physical Layer) • Advantage • Extend cable length • Disadvantage • Also propagate the noise
HUB • Connects multiple nodes in a single network segment • Works at Layer One (Physical Layer) • Broadcasting Device • Multi-port Repeater • Detects and troubleshoots collisions • Became Obsolete
Bridge • Used for Network Segmentation at Layer two • Segmentation • Dividing a big network into parts • Advantage • Less Collisions • More Bandwidth • Makes MAC table • Intelligence Device (Make Decisions)
Switch • Similar to HUB but is an intelligent device • Forwards Packets based upon their destination address • Increase bandwidth • A switch gives any device on the network the full bandwidth instead of sharing the available bandwidth. • Intelligence ensures only destination receives the data, at maximum bandwidth. • Decrease collisions • Direct Connection between multiple hosts
Switch • Also known as Multi-port Bridge • Store & Forward Device • Store & Forward Vs Cut through • MAC Table • Typically works on Layer 2 • Layer 3 Switches are also available • Advance Switches are manageable • MAC Filtering • SNMP (Simple Network Management Protocol) • VLAN Setting
Router • A router is a device that forwards data packets from one network to another. • Routers read the network address in order to route data via the optimum path. • Data packets which are addressed to a device at the same site of the router will not be let through. • Convert data structure from one media to another, for example Ethernet <=> ISDN. • Routers can interconnect all networks in the enterprise. • For example two different networks like a LAN and the Internet
Router • Also Performs Segmentation • Layer 3 Segmentation based upon IP (logical address) • Performs switching as switch • Best Path Selection based upon Network address • Encapsulation/De-encapsulation of Packet • Routing Table
Gateway • Some times router may be used as a Gateway • Gateway is an essential functionality provided by router • It is a node that serve as entrance to another network and vice versa • Normally used between private networks and internet • Any packet whose address doesn’t belong to current network is forwarded to gateway • Gateway may/may not perform NAT