Network Basics and Internet Week 7

Computer Network Hierarchy
-Every computer is connected to part of a network
-ISP (internet service provider)
-LAN (local area network)]
-a network of networks
-POP (point of presence)
-NAPS (network access points)

Router
-determine whether to send information
-info doesn't go where its not needed
-info makes it to intended destination

Backbones
-NSF created first one in 1987
-fiber optic trunk lines

IP Addresses
-unique identifying number
-lang. comps used to communicate over internet
-four numbers called octets

URL
-TLD:COM, .ORG, .NET, .EDU and .GOV

DNS(domain name system)
It can answer the request with an IP address because it already knows the IP address for the requested domain.
It can contact another DNS server and try to find the IP address for the name requested. It may have to do this multiple times.
It can say, "I don't know the IP address for the domain you requested, but here's the IP address for a DNS server that knows more than I do."
It can return an error message because the requested domain name is invalid or does not exist.