Firewalls and proxy servers Flashcards
What is a firewall?
Software or hardware that sits between the user’s computer and the internet or external network. It filters information going into and out of the computer.
What is a proxy server?
This is a computer that acts as an intermediary between the user’s computer and a web server
How do proxy servers use cache to speed up access to information on a website?
When the website is first visited, the homepage is stored on the proxy server. When the user visits the website again, the computer goes through the proxy server cache instead.
What can a firewall prevent from gaining access to a user’s computer?
viruses or hackers
What warning can a firewall give to a user
Warns user of attempts by sofware trying to access external data sources
How does a firewall allow the user to later interrogate traffic?
It logs all incoming and outgoing traffic
What access can be blocked by a firewall?
Access to specified IP addresses or websites
How is incoming and outgoing traffic checked by a firewall?
The firewall checks whether incoming or outgoing traffic meets a given set of criteria
What happens when traffic doesn’t meet criteria?
It is blocked by the firewall
What does a firewall examine?
Traffic to and from the user’s computer
What does a proxy server do to traffic?
It filters the traffic
When does the proxy server allow data from a web server to be obtained by the user?
When the traffic from the web server is valid
What happens when a proxy server detects invalid traffic from a web sever?
The request by the user to obtain data from the web server is denied
How can a proxy server provide security for a web server?
Directs invalid traffic away from the web server
What can proxy server’s block
Blocks requests from certain IP addresses
