Why Is a Firewall Necessary?


Quick Answer

A firewall is necessary because it blocks unauthorized access to private networks, safeguarding them from hackers, viruses and worms. A firewall works by monitoring all messages entering and leaving the intranet and restricting those that do not meet security data. A firewall can take the form of hardware, software or a combination of both. Some of the most common forms are packet filtering, circuit-level gateway implementation and web application firewalls.

Continue Reading
Related Videos

Full Answer

Hackers, viruses and other online threats put computer users at risk of information theft and jeopardized computer performance. A firewall acts as the first line of defense against these threats. It checks network traffic and connections but does not authenticate individual users for access to a network.

In packet filtering, the system examines the packets that enter and leave the network. User-defined rules determine whether access is granted or declined. Packet filtering is susceptible to IP spoofing, the creation of IP packets with a forged IP address.

Circuit-level gateway implementation applies security mechanisms whenever a TCP or UDP is established. Upon authentication of a connection, packets flow between hosts without further revision.

A web application firewall is a hardware filter, such as a sever plug-in, that applies a pre-formulated set of rules to a HTTP conversation, thereby identifying and blocking attacks from malevolent sources.

Learn more about Internet & Networking

Related Questions