Networking Flashcards
TCP
Transport Control Protocol
IP
Internet Protocol
Application Layer Protocol
Decides how applications talk to each other
Network Protocol
The connection established between two systems
HTTP
Hypertext Transfer Protocol
SMTP
Simple Message Transfer Protocol
IP address is
A 32 bit number presented as a decimal number in 4 segments
Port Number
16 bit number that ranges from 0-65535
Socket
A virtual construct, made up of an IP address and a port number
FQDN
Fully Qualified Domain Name, a name mapped to an IP address, the service that provides the mapping is called DNS
Client Process
Initializes the connection to a server process and sends its request
Server Process
Listens for client connections, accepts connections frim clients, recieves and processes their requests and returns a response
PING
Package Internet Groper, tests connectivity between two hosts
NS LOOK UP
Used to look up IP addresses of hosts
TELNET
Used to connect remote hosts
Client Process
Seeks the service of a server process
•opens a network connections
•sends a request
•recieves response
•closes connection
•java.net.Socket represents a client socket
Server Process
Provides a service to clients, is always listening
•attaches itself to a specific network
•accepts client connection, establishes two-way communication channel
•recieves client requests, processes it
•sends response back
•java.net.ServerSocket
java.net
•java.net.Socket: represents a client network
•java.net.ServerSocket: Represents a server process
HTTP Protocol
•The client ( a wev browser) opens a network connection in port 80 for plain text or 443 for encrypted
•client sends http request using specific syntax
•server recieves request
HTTP Request
•Request Keyword: specifies the nature of the request
•Resource: the actual resource you are looking for
•Header: additional information
•Optional HTTP Version number that can be added
HTTP Request Keywords
•GET: This specifies that you are asking the server to return you the resource you are looking for
•HEAD: You are asking for the server to only return HTTP headers
Header
Additional information like:
•browser type
•version
•cookies
HTTP Response
•Response Code: Has a number and a string, indicates whether request was successful
•Header: Similar to request header, contains additional infi
•Body: Contains actual Response
Common HTTP Codes
•200 - Ok: Request was successful
•404 - Not Found
•400 - Bad Request
•301 - Moved Permanently
•302 - Moved Temporarily
