Unformatted text preview: IP Internet (uppercase "I") is the most famous example of an internet (lowercase "i") Let's see how an internet is built from the ground up Carnegie Mellon Lowest Level: Ethernet Segment host 100 Mb/s host hub host 100 Mb/s port Ethernet segment consists of a collec8on of hosts connected by wires (twisted pairs) to a hub Spans room or floor in a building Opera8on Each Ethernet adapter has a unique 48-bit address (MAC address) E.g., 00:16:ea:e3:54:e6 Hosts send bits to any other host in chunks called frames Hub slavishly copies each bit from each port to every other port Every host sees every bit Note: Hubs are on their way out. Bridges (switches, routers) became cheap enough to replace them (means no more broadcas2ng) Carnegie Mellon Next Level: Bridged Ethernet Segment A host host B host host host X hub 100 Mb/s bridge 100 Mb/s hub 1 Gb/s hub host host 100 Mb/s bridge Y host 100 Mb/s host hub host host host C Spans building or campus Bridges cleverly learn which hosts are reachable from which ports and then selec8vely copy frames from port to port Carnegie Mellon...
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- Spring '13
- Networking, IP address, Domain Name System