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H
HTTP
HTTPS
I
ICMP
IEEE 802.1X
HTTP is an acronym for Hypertext Transfer Protocol. It is a protocol that used to
transfer or convey information on the World Wide Web (WWW).
HTTP defines how messages are formatted and transmitted, and what actions Web
servers and browsers should take in response to various commands. The other main
standard that controls how the World Wide Web works is HTML, which covers how
Web pages are formatted and displayed.
Any Web server machine contains, in addition to the Web page files it can serve, an
HTTP daemon, a program that is designed to wait for HTTP requests and handle
them when they arrive. The Web browser is an HTTP client, sending requests to
server machines. An HTTP client initiates a request by establishing a Transmission
Control Protocol (TCP) connection to a particular port on a remote host (port 80 by
default). An HTTP server listening on that port waits for the client to send a request
message.
HTTPS is an acronym for Hypertext Transfer Protocol over Secure Socket Layer. It is
used to indicate a secure HTTP connection.
HTTPS provide authentication and encrypted communication and is widely used on
the World Wide Web for security-sensitive communication such as payment
transactions and corporate log-ons.
HTTPS is really just the use of Netscape's Secure Socket Layer (SSL) as a sub-layer
under its regular HTTP application layering. (HTTPS uses port 443 instead of HTTP
port 80 in its interactions with the lower layer, TCP/IP.) SSL uses a 40-bit key size for
the RC4 stream encryption algorithm, which is considered an adequate degree of
encryption for commercial exchange.
ICMP is an acronym for Internet Control Message Protocol. It is a protocol that
generated the error response, diagnostic or routing purposes. ICMP messages
generally contain information about routing difficulties or simple exchanges such as
time-stamp or echo transactions.
IEEE 802.1X is an IEEE standard for port-based Network Access Control. It provides
authentication to devices attached to a LAN port, establishing a point-to-point
connection or preventing access from that port if authentication fails. With 802.1X,
access to all switch ports can be centrally controlled from a server, which means that
authorized users can use the same credentials for authentication from any point
within the network.
