A firewall is a part of a computer system
or network that is designed to block
unauthorised access while permitting outward communication. Firewalls can be
implemented in both hardware and software , or combination of both . A firewall is a dedicated appliance or
software running on computer which inspects network traffic passing through it
and defines or permits passage based on a set of rules . There are several
types of firewall techniques available , they are the followings
Packet-filter
It looks each packet entering or leaving
the networks and accept or rejects it based on user defined rules
Application gateway
Applies security mechanisms to specific
applications such as ftp,telnet etc
Circuit level gateway
Applies security mechanisms when a tcp or
udp connection is established .
Proxy server
Intercepts all messages entering and
leaving the network . The proxy server effectively hides the true network
address
0 comments:
Post a Comment