The Firewall Essay -- Technology Computers Internet Safety Essays

The Firewall WHAT IS A NETWORK FIREWALL?A firewall is a system or group of systems that enforces an access control polity between two or more profits. The means by which this control is accomplished varies widely, but in principle, the firewall is a pair of mechanisms, one that blocks traffic and one that suffers traffic. Some firewalls emphasize jam traffic, while others emphasize permitting traffic. The most important thing to recognize about a firewall is that it implements an access control policy. If you dont know what kind of access you want to permit or deny, or you let someone else or some product configure a firewall based on judgment other than yours, that entity is making policy for your whole organization.WHY WOULD I WANT A FIREWALL?The Internet is a fun little playground and at the same time a strange environment. Like any other society, its plagued with the kind of people who enjoy the electronic equivalent of writing on other peoples walls with spray paint, tearin g finish their mailboxes, or just sitting in the street blowing their car horns. Some people get real work done over the Internet, and some must hold dear sensitive or proprietary data. Usually, a firewalls purpose is to keep the intruders out of your network while letting you do your job.Many traditional corporations and data centers fill computing security policies and practices that users must follow. If a companys policies dictate how data must be protected, a firewall is very important because it embodies somatic policy. Frequently, the hardest part of hooking a large company to the Internet is not justifying the expense or effort, but instead convincing management that its safe to do so. A firewall not still provides real security but also plays an important role as a security blanket for management.Last, a firewall can act as your corporate ambassador to the Internet. Many corporations use their firewall systems to store public information about corporate products and se rvices, files to download, bug-fixes, and so forth. Several of these systems (such as uunet.uu.net, whitehouse.gov, gatekeeper.dec.com) have become important split of the Internet service structure and reflect well on their organizational sponsors.WHAT CAN A FIREWALL PROTECT AGAINST?Some firewalls permit only e-mail traffic, thereby protecting the network against any attacks o... ...ng it, crashing it, jamming it, or flooding it. Denial of service is impossible to prevent because of the distributed nature of the network every network thickening is connected via other networks, which in turn connect to other networks. A firewall administrator or ISP has control of only a few of the local elements in spite of appearance reach. An attacker can always disrupt a connection upstream from where the victim controls it. In other words, someone who wants to take a network off the air can either take the network off the air directly or take the network it connects to off the air, or the ne twork that connects to that network off the air, ad infinitum. Hackers can deny service in many ways, ranging from the complex to the brute-force. If you are considering using the Internet for a service that is absolutely time- or mission-critical, you should consider your fallback position in the event that the network is down or damaged. Microsoft has released hotfixes that address certain types of denial-of-service attacks such as SYN Flooding and giant bump packets. Be sure to regularly watch for new Service Packs, because they offer new security enhancements that you should put on your systems.