CSC 100 Lecture Notes - Lecture 7: Post Office Protocol, Hostname, Keystroke Logging

• School: University of Victoria
• Department: Computer Science
• Course: CSC 100
• Professor: Cheng Mantis

Document Summary

To use world wide we(cid:271) ser(cid:448)i(cid:272)e of a parti(cid:272)ular ser(cid:448)er, (cid:449)e use port (cid:862)8(cid:1004)(cid:863). To use pop3 (post office protocol) email service, we use port (cid:862)(cid:1005)(cid:1005)(cid:1004)(cid:863). To use sftp (secure ftp) service, we use port. If an ip address is a telephone number, then a port number is similar to a local (cid:862)exte(cid:374)sio(cid:374)(cid:863). There are over 1000 well known port numbers. A protocol is a set of rules on how computers communicate with each other. The internet is based on the tcp/ip (transmission control protocol/internet protocol) protocols. It is (cid:271)ased o(cid:374) the idea of (cid:862)postcards(cid:863) (cid:894)k(cid:374)o(cid:449)(cid:374) as packets). It is small and has a fixed size. The message body is limited. (cid:894)you (cid:272)a(cid:374)"t (cid:449)rite too (cid:373)a(cid:374)(cid:455) (cid:449)ords. (cid:895) Each computer on the internet has a globally unique ip address, like a (cid:862)pho(cid:374)e (cid:374)u(cid:373)(cid:271)er(cid:863). Each part is a number, ranging from 0 to 2. You need the ipaddress of another computer in order to communicate with it.