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The potential damages caused by stolen personal info like credit-card information far outweighs the purchase price of today's good Firewall software or hardware, its essential that you carefully select a good firewall and learn to set it up correctly.
The price difference between an inadequate firewall and a robust, effective firewall is minimal. It is more important to properly configure a good firewall than to buy the most expensive or complex.
Personal - If you just have one computer directly accessing the internet via a modem (Broadband connections are more susceptible to intrusions due to its always connected nature), it most cost effective to just use a good firewall software on that computer. A good software firewall is already configured to protect you from known threats and is updated automatically to tackle new threats. You may also want to consider proven firewall and antivirus suites . Save you money and easier configuration via a single user menu.
Small Office - If you have more than one computer that needs internet access in your office or home, you would most likely have some firewall like features built into your router. All hardware firewalls uses Network Address Translation (NAT) that shields internal network computers from the internet.
Alternatively, you can also install a software network firewall on your network access computer - gives much more control of firewall features.
Unfortunately, a hardware firewall does not provide much protection from worms, spy wares or Trojans that can shift confidential and damaging data out of one of your computers. You would need a software firewall on each individual computer for adequate protection these days.
Traveler - A software firewall is almost the only choice for notebook users - lugging an external firewall + power supply defeats having one of those nice Pentium-M lightweights. Also, software firewalls can be updated with tighter security features as fast as new threats surfaces. Many of today's security threats come from application level embedded codes (from emails or websites) that send confidential data to an external party.
We hope that the above will help your internet security shopping decision making.
A network Firewall is some dedicated hardware or software that tries to prevent unauthorized access of outside network traffic to individual computers (personal firewall) or to a group of computers. Some firewalls also block the outflow of data 'packets' from unauthorized programs in the protected computer.
Firewalls typically adopt one or more of the following methods to secure traffic flowing in and out of a computer/group of computers,
Network Address Translation (NAT) - works from within a network router to translate the service provider's assigned IP address to multiple addresses within the internal network. This hides the IP address of each individual computer in the network from scanners software in the internet.
Packet Filtering - inspects each packet of network data going in and out of the firewall (packet filtering is usually hardware implemented) and accepts or reject packets based on a configured set of access policy. Most network routers implement some sort of packet filtering, it???s cheap and fast but difficult to configure for heightened levels of security. This is because packet filters looks at source & destination IP addresses, ports and protocols but not at content or purpose of the packets (e.g. it does not does not know that the packet is an outgoing Outlook email).
Stateful Packet Inspection (SPI) - instead of inspecting each data packet independently, SPI filtering looks at certain characteristics of flow of data packets and compares against its sets of configured rules. This allows more intelligent decision but usually requires user intervention from within the firewall software.
Application Level Proxy Server - a software solution where an intermediary application secures the data traffic going in and out of a system from a particular application. When an application needs to send data to the internet, the proxy servers performs the connection and pass/fails the transaction based on earlier user configuration. As the process is done on a proxy server (internal or external), network performance always degraded.
If you work at a large corporation, odds are good that a Firewall sits between you and the outside world. But the increased availability of cable and DSL service means you could spend more time connected to the Internet from home--and more time as a potential target for hackers. You're somewhat vulnerable even on short dial-up connections. Unfortunately, most people become aware of the danger only after they become victims. With cyber attacks increasing, it is predicted that firewalls will be ubiquitous in five or six years.
But you don't have to buy an expensive, hard-to-maintain security system for your PC. Personal firewalls, usually based on the application gateway model, can keep you safe. These products don't require you to program complex restrictions. They'll guide you through a setup that asks you what you want to allow or block. They can also help you monitor intrusion attempts and protect you from most Trojan horse or spy ware programs that let a hacker control your computer over the Internet. They can hide your identity while you surf, too. On the basis of their iniquitousness, firewalls Move into the Mainstream
While most personal firewalls are available now as software that you install on your PC, some experts predict that firewalls will be integrated into hardware in the next few years. That means the next DSL or cable modem you buy or lease may have a firewall already installed. To make maintaining a firewall easy, they say, companies will offer subscription services. Maybe You just need to pay $50 a month and the company will make sure your firewall is up-to-date. That maintenance is key to keeping your data safe: As soon as hackers hear about a weakness in a firewall, they hunt for people who haven't upgraded to the latest version and break in.
As our dependence on the Internet and computers grows, so will the personal consequences of a security breach? Whether to protect your personal information from theft or to keep your PC from being hijacked by a hacker, installing a personal firewall makes sense.
Personal Firewall is a technology that helps prevent intruders from accessing data on your PC via the Internet or another network, by keeping unauthorized data from entering or exiting your system.
Hackers don't just target national security organizations for cyber attacks: They want your tax returns, network passwords, or bank account numbers. And you don't want the FBI kicking in your door because someone hijacked your PC to participate in the latest denial-of-service attack on the Internet. Now that "always-on" broadband connections such as cable modems and digital subscriber line are becoming more popular, home users are at risk. Fortunately, you can protect your data with a kind of security utility--firewalls.
Firewalls can block malicious attacks and protect your PC from outside threats. A firewall can prevent an unauthorized user from accessing your PC, either from the Internet or from within your local network. It blocks some Trojan horse programs and many hostile applications that seek to take over your computer.
When you're connected to the Internet, you're sending and receiving information in small units called packets. A packet contains the addresses of the sender and the recipient along with a piece of data, a request, a command, or almost anything having to do with your connection to the Internet. But just as with postal mail, not every package that arrives at your computer is one you want to open.
A firewall examines each data packet sent to or from your computer to see if it meets a set of criteria. The firewall then selectively passes or blocks the packet.
The criterion a firewall uses for passing packets along depends on the kind of firewall you use. The most common type you'll find for home and small business use is called an application gateway firewall.
An application gateway, often called a proxy, acts like a customs officer for data: Anything you send or receive stops first at the firewall, which filters packets based on IP addresses and content, as well as the specific functions of an application. For instance, if you're running an FTP program, the proxy could permit file uploads while blocking other FTP functions, such as viewing or deleting files. You can also set the firewall to ignore all traffic for FTP services but allow all packets generated during Web browsing.
Other kinds of firewalls include packet filters, which examine every packet for an approved IP address; circuit-level firewalls, which allow communication only with approved computers and Internet service providers; and the newest type, stateful inspection firewalls, which note the configuration of approved packets and then pass or block traffic based on those characteristics.
Packet-filter, circuit-level, and stateful inspection firewalls are mostly found in corporate network setups. They require major upkeep, so they aren't suitable for smaller companies and home users.
It is necessary for us to approach the task of implementing a Firewall by going through the following steps:
a. Determine the access denial methodology to use.
It is recommended you begin with the methodology that denies all access by default. In other words, start with a gateway that routes no traffic and is effectively a brick wall with no doors in it.
b. Determine inbound access policy.
If all of your Internet traffic originates on the LAN this may be quite simple. A straightforward NAT router will block all inbound traffic that is not in response to requests originating from within the LAN. The true IP addresses of hosts behind the firewall are never revealed to the outside world, making intrusion extremely difficult. Indeed, local host IP addresses in this type of configuration are usually non-public addresses, making it impossible to route traffic to them from the Internet. Packets coming in from the Internet in response to requests from local hosts are addressed to dynamically allocated port numbers on the public side of the NAT router. These change rapidly making it difficult or impossible for an intruder to make assumptions about which port numbers to use.
If your requirements involve secure access to LAN based services from Internet based hosts, then you will need to determine the criteria to be used in deciding when a packet originating from the Internet may be allowed into the LAN. The stricter the criteria, the more secure your network will be. Ideally you will know which public IP addresses on the Internet may originate inbound traffic. By limiting inbound traffic to packets originating from these hosts, you decrease the likelihood of hostile intrusion. You may also want to limit inbound traffic to certain protocol sets such as ftp or http. All of these techniques can be achieved with packet filtering on a NAT router. If you cannot know the IP addresses that may originate inbound traffic, and you cannot use protocol filtering then you will need more a more complex rule-based model and this will involve a stateful multilayer inspection firewall.
c. Determine outbound access policy.
If your users only need access to the web, a proxy server may give a high level of security with access granted selectively to appropriate users. As mentioned, however, this type of firewall requires manual configuration of each web browser on each machine. Outbound protocol filtering can also be transparently achieved with packet filtering and no sacrifice in security. If you are using a NAT router with no inbound mapping of traffic originating from the Internet, then you may allow LAN users to freely access all services on the Internet with no security compromise. Naturally, the risk of employees behaving irresponsibly with email or with external hosts is a management issue and must be dealt with as such.
d. Determine if dial-in or dial-out access is required.
Dial-in requires a secure remote access PPP server that should be placed outside the firewall. If dial-out access is required by certain users, individual dial-out computers must be made secure in such a way that hostile access to the LAN through the dial-out connection becomes impossible. The surest way to do this is to physically isolate the computer from the LAN. Alternatively, personal firewall software may be used to isolate the LAN network interface from the remote access interface.
e. Decide whether to buy a complete firewall product, have one implemented by a systems integrator or implement one yourself.
Once the above questions have been answered, it may be decided whether to buy a complete firewall product or to configure one from multipurpose routing or proxy software. This decision will depend as much on the availability of in-house expertise as on the complexity of the need. A satisfactory firewall may be built with little expertise if the requirements are straightforward. However, complex requirements will not necessarily entail recourse to external resources if the system administrator has sufficient grasp of the elements. Indeed, as the complexity of the security model increases, so does the need for in-house expertise and autonomy.
Conceptually, there are two types of Firewalls: Network layer and Application layer.
They are not as different as you might think, and latest technologies are blurring the distinction to the point where it's no longer clear if either one is ``better'' or ``worse.'' As always, you need to be careful to pick the type that meets your needs.
Which is which depends on what mechanisms the firewall uses to pass traffic from one security zone to another? The International Standards Organization (ISO) Open Systems Interconnect (OSI) model for networking defines seven layers, where each layer provides services that ``higher-level'' layers depend on. In order from the bottom, these layers are physical, data link, network, transport, session, presentation, application.
The important thing to recognize is that the lower-level the forwarding mechanism, the less examination the firewall can perform. Generally speaking, lower-level firewalls are faster, but are easier to fool into doing the wrong thing.
Network layer firewalls
These generally make their decisions based on the source, destination addresses and ports in individual IP packets. A simple router is the ``traditional'' network layer firewall, since it is not able to make particularly sophisticated decisions about what a packet is actually talking to or where it actually came from. Modern network layer firewalls have become increasingly sophisticated, and now maintain internal information about the state of connections passing through them, the contents of some of the data streams, and so on. One thing that's an important distinction about many network layer firewalls is that they route traffic directly through them, so to use one you either need to have a validly assigned IP address block or to use a ``private internet'' address block. Network layer firewalls tend to be very fast and tend to be very transparent to users.
Application layer firewalls
These generally are hosts running proxy servers, which permit no traffic directly between networks, and which perform elaborate logging and auditing of traffic passing through them. Since the proxy applications are software components running on the firewall, it is a good place to do lots of logging and access control. Application layer firewalls can be used as network address translators, since traffic goes in one ``side'' and out the other, after having passed through an application that effectively masks the origin of the initiating connection. Having an application in the way in some cases may impact performance and may make the firewall less transparent. Early application layer firewalls are not particularly transparent to end users and may require some training. Modern application layer firewalls are often fully transparent. Application layer firewalls tend to provide more detailed audit reports and tend to enforce more conservative security models than network layer firewalls.
The Future of firewalls lies someplace between network layer firewalls and application layer firewalls. It is likely that network layer firewalls will become increasingly ``aware'' of the information going through them, and application layer firewalls will become increasingly ``low level'' and transparent. The end result will be a fast packet-screening system that logs and audits data as it passes through. Increasingly, firewalls (network and application layer) incorporate encryption so that they may protect traffic passing between them over the Internet. Firewalls with end-to-end encryption can be used by organizations with multiple points of Internet connectivity to use the Internet as a ``private backbone'' without worrying about their data or passwords being sniffed.
Firewall - Personal Firewall - Firewall Download - Firewall Software - Firewall Protection
A personal Firewall is the most important first line of defense for computer security. It's a piece of software or hardware that creates a protective barrier between your computer and potentially harmful content on the Internet. Think of it as a wall around your computer--a wall that lets only approved traffic through. It helps keep hackers out, and stops the spread of many computer viruses and worms.
The best personal firewalls not only keep threats from getting on your computer, but they also keep threats already on your PC from getting out. Keeping your computer from infecting others is the responsible thing to do.
The following resources provide more information about some firewall options.
How a Firewall Works
A firewall is hardware, software, or a combination of both that is used to prevent unauthorized programs or Internet users from accessing a private network. All information entering or leaving the network must pass through the firewall, which examines the information packets and blocks those that do not meet the security criteria. A personal firewall performs these functions for a single computer--and usually as a software program, as opposed to a hardware device.
A personal firewall protects in a variety of ways, which can be summarized into three categories of firewall rules:
Allow: The Personal Firewall Allows some traffic to flow. This is usually traffic that is known to be "safe", usually because you have defined it, application by application, to be "safe."
Block: The Personal Firewall Blocks some traffic. This is usually traffic that is known to be problematic or dangerous to your computer.
Ask: The Personal Firewall Asks whether incoming and outgoing traffic is allowed to access your computer or an organization's network resources. When you run the Firewall, it initially asks you whether to permit your applications to access network resources. Optionally, it remembers your responses, so that you do not have to tell it again.
By using firewall rules, the Personal Firewall can systematically Allow, Block, or Ask about what action to take on incoming traffic from specific IP addresses and ports. The configuration of those rules with other security settings provides a security agent that protects your computer.
Hardware Firewalls
if you are protecting a group of linked computers--otherwise known as a network--you might want to get a hardware firewall, which protects the entire network against outside attacks. Some home networking hardware, like wireless access points and broadband routers, come with built-in hardware firewalls. You'll still need to use a personal firewall, though, because personal firewalls can easily stop "outbound" threats.
Hardware firewalls can be quite complex, so if you're new to computer security, you should ask someone more knowledgeable to help configure a hardware firewall.
Firewall - Personal Firewall - Firewall Download - Firewall Software - Firewall Protection
A Firewall is simply a program or hardware device that filters the information coming through the Internet connection into your private network or computer system. If an incoming packet of information is flagged by the filters, it is not allowed through.
Let's say that you work at a company with 500 employees. The company will therefore have hundreds of computers that all have network cards connecting them together. In addition, the company will have one or more connections to the Internet through something like T1 or T3 lines. Without a firewall in place, all of those hundreds of computers are directly accessible to anyone on the Internet. A person who knows what he or she is doing can probe those computers, try to make FTP connections to them, try to make Internet connections to them and so on. If one employee makes a mistake and leaves a security hole, hackers can get to the machine and exploit the hole.
With a firewall in place, the landscape is much different. A company will place a firewall at every connection to the Internet (for example, at every T1 line coming into the company). The firewall can implement security rules.
Firewalls use one or more of three methods to control traffic flowing in and out of the network:
Packet filtering - Packets (small chunks of data) are analyzed against a set of filters. Packets that make it through the filters are sent to the requesting system and all others are discarded.
Proxy service - Information from the Internet is retrieved by the firewall and then sent to the requesting system and vice versa.
State inspection - A newer method that doesn't examine the contents of each packet but instead compares certain key parts of the packet to a database of trusted information. Information traveling from inside the firewall to the outside is monitored for specific defining characteristics, then incoming information is compared to these characteristics. If the comparison yields a reasonable match, the information is allowed through. Otherwise it is discarded.
A firewall blocks unwanted access to the protected network while giving the protected network access to networks outside of the firewall. A company will typically install a firewall to give users??? access to the Internet while protecting their internal information consequently.
Firewall - Personal Firewall - Firewall Download - Firewall Software - Firewall Protection
Notwithstanding some happening, the Internet doesn???t have to be a scary place. Just as you lock the front door to your home, it???s important to protect your PC. One of the best ways to protect your PC or your home or small business network from malicious hackers is to use a Firewall. Consumer-level firewalls provide good security without requiring that you be a computer security expert.
What is a Firewall?
A firewall is a security system designed to prevent unauthorized access from the Internet to or from your network. A firewall works by screening out many types of malicious traffic. In addition, firewalls can help keep your computer from participating in attacks on others without your knowledge. Firewalls take the form of hardware, software, or both and I will do some explanation about various kinds of firewalls and will help you choose the right one for your network.
Hardware firewall
Hardware firewall products protect your computer and home network by guarding your Internet connection and filtering any requests that you haven???t specifically allowed. Software firewalls are installed directly on your PC, and filter requests after they reach your computer.
For maximum security, the most reliable way for home users to protect a network is to purchase a router with firewall capabilities. These routers do more than act as a firewall???they network multiple computers, allow them to share a single Internet connection, and may even support wireless networking. If you have more than one computer and an always-on broadband connection, a router-firewall gives you the benefits of a home network and connects every computer to the Internet. If you bring a laptop home from work, it may even be a requirement of your company???s security policy.
The router is generally a separate device from the cable or DSL modem???it???s important to understand that most cable and DSL modems offer your home network no protection whatsoever. If you didn???t choose to pay extra for security features, you probably don???t have any. If you???re unsure about your modem, ask your Internet service provider (ISP) what level of protection your modem provides.
Software Firewalls
Software firewalls are often less expensive and easier to configure than hardware firewalls. Software firewalls also don???t require you to move any cables around. Depending on the software you choose, a software firewall can offer features beyond those of router firewalls, such as protecting your computer from spy ware (a component of some free software that tracks your Web browsing habits) and Trojan horses ( a program that claims to do one thing, but does another, malicious thing, such as recording your passwords. If you travel with a laptop, a software firewall is a necessity???you need protection wherever you connect to the Internet, and your hardware firewall can protect you only at home.
To Choose Hardware or Software Firewall?
You wouldn???t park your car and leave your keys in the ignition, and you shouldn???t connect to the Internet without a personal firewall. No matter what type of computer or network you have, there???s a firewall to meet your needs.
If you have a stand-alone computer or connect to the Internet with a dial-up connection, a software firewall is the right choice. A hardware firewall is more complex to configure, but once you get it set up; it runs on its own to protect your network.
Can firewall replace anti-virus software?
Note that firewall software does not replace anti-virus software so you should use both to protect your network.
So combined with a software-based firewall, you???ve got maximum security for your network. And whichever you choose, you???ll find using the Internet much more enjoyable when you???re nestled safely behind a firewall.
1 What is a firewall?
A firewall is a system or group of systems that enforces an access control policy between two networks. The actual means by which this is accomplished varies widely, but in principle, the firewall can be thought of as a pair of mechanisms: one which exists to block traffic, and the other which exists to permit traffic. Some firewalls place a greater emphasis on blocking traffic, while others emphasize permitting traffic. Probably the most important thing to recognize about a firewall is that it implements an access control policy. If you don't have a good idea of what kind of access you want to allow or to deny, a firewall really won't help you. It's also important to recognize that the firewall's configuration, because it is a mechanism for enforcing policy, imposes its policy on everything behind it. Administrators for firewalls managing the connectivity for a large number of hosts therefore have a heavy responsibility.
2 Why would I want a firewall?
The Internet, like any other society, is plagued with the kind of jerks who enjoy the electronic equivalent of writing on other people's walls with spray-paint, tearing their mailboxes off, or just sitting in the street blowing their car horns. Some people try to get real work done over the Internet, and others have sensitive or proprietary data they must protect. Usually, a firewall's purpose is to keep the jerks out of your network while still letting you get your job done. Many traditional-style corporations and data centers have computing security policies and practices that must be adhered to. In a case where a company's policies dictate how data must be protected, a firewall is very important, since it is the embodiment of the corporate policy. Frequently, the hardest part of hooking to the Internet, if you're a large company, is not justifying the expense or effort, but convincing management that it's safe to do so. A firewall provides not only real security--it often plays an important role as a security blanket for management. Lastly, a firewall can act as your corporate "ambassador" to the Internet. Many corporations use their firewall systems as a place to store public information about corporate products and services, files to download, bug-fixes, and so forth. Several of these systems have become important parts of the Internet service structure and have reflected well on their organizational sponsors.
3 What can a firewall protect against?
Some firewalls permit only email traffic through them, thereby protecting the network against any attacks other than attacks against the email service. Other firewalls provide less strict protections, and block services that are known to be problems.
Generally, firewalls are configured to protect against unauthenticated interactive logins from the "outside" world. This, more than anything, helps prevent vandals from logging into machines on your network. More elaborate firewalls block traffic from the outside to the inside, but permit users on the inside to communicate freely with the outside. The firewall can protect you against any type of network-borne attack if you unplug it.
Firewalls are also important since they can provide a single "choke point" where security and audit can be imposed. Unlike in a situation where a computer system is being attacked by someone dialing in with a modem, the firewall can act as an effective "phone tap" and tracing tool. Firewalls provide an important logging and auditing function; often they provide summaries to the administrator about what kinds and amount of traffic passed through it, how many attempts there were to break into it, etc.
This is an important point: providing this "choke point" can serve the same purpose on your network as a guarded gate can for your site's physical premises. That means anytime you have a change in "zones" or levels of sensitivity, such a checkpoint is appropriate. A company rarely has only an outside gate and no receptionist or security staff to check badges on the way in. If there are layers of security on your site, it's reasonable to expect layers of security on your network.
Firewall - Personal Firewall - Firewall Download - Firewall Software - Firewall Protection
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