Firewall-SonicWall Introduction

What is firewall and what is the purpose of firewall?

A firewall is a part of a computer system or network that is designed to block unauthorized access while permitting authorized communications. It is a device or set of devices configured to permit, deny, encrypt, decrypt, or proxy all (in and out) computer traffic between different security domains based upon a set of rules and other criteria.

Firewalls can be implemented in either hardware or software, or a combination of both. Firewalls are frequently used to prevent unauthorized Internet users from accessing private networks connected to the Internet, especially intranets. All messages entering or leaving the intranet pass through the firewall, which examines each message and blocks those that do not meet the specified security criteria.

How Firewall works?

If you have been using the Internet for any length of time, and especially if you work at a larger company and browse the Web while you are at work, you have probably heard the term firewall used. For example, you often hear people in companies say things like, "I can't use that site because they won't let it through the firewall."

If you have a fast Internet connection into your home (either a DSL connection or a cable modem), you may have found yourself hearing about firewalls for your home network as well. It turns out that a small home network has many of the same security issues that a large corporate network does. You can use a firewall to protect your home network and family from offensive Web sites and potential hackers. 

Basically, a firewall is a barrier to keep destructive forces away from your property. In fact, that's why its called a firewall. Its job is similar to a physical firewall that keeps a fire from spreading from one area to the next. As you read through this article, you will learn more about firewalls, how they work and what kinds of threats they can protect you from.

What Firewall Software Does?

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.

If you have read the article How Web Servers Work, then you know a good bit about how data moves on the Internet, and you can easily see how a firewall helps protect computers inside a large company. 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 telnet 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. For example, one of the security rules inside the company might be:

Out of the 500 computers inside this company, only one of them is permitted to receive public FTP traffic. Allow FTP connections only to that one computer and prevent them on all others.

A company can set up rules like this for FTP servers, Web servers, Telnet servers and so on. In addition, the company can control how employees connect to Web sites, whether files are allowed to leave the company over the network and so on. A firewall gives a company tremendous control over how people use the network.

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.

Stateful 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.

Who are the firewall producers?

Product Name	Description
AccessMaster NetWall (Evidian)	Providing high-end security with complete multi-level control, NetWall provides a powerful solution to easy, centralized network security management, whether the deployment involves tens or hundreds of sites. Advanced security features include stateful IP filtering, application proxies, NAT, IPSEC VPN, ITSEC E3 certification, a broad range of authentication schemes, integration with anti-virus and content checking, load balancing and 24x7 availability, LDAP support and centralized management, alerts, audit and reporting.
BorderManager (Novell)	Helps businesses protect systems and strengthen network borders.
BorderWare Firewall Server	A comprehensive integrated solution for securing your internet connection. Built on a hardened operating system, it eliminates vulnerabilities and costs associated with a separate firewall and operating system. Running on standard Intel platforms, BorderWare can install on easily available hardware, which can be upgraded to grow as your internet requirements expand.
Cisco Secure PIX Firewall (Cisco Systems)	Dedicated firewall appliance. Delivers strong security without impacting network performance. The product line scales to meet a range of customer requirements, and three capacity license levels. The Cisco Secure PIX Firewall is the leading product in its segment of the firewall market. The Cisco Secure PIX Firewall provides full firewall protection that completely conceals the architecture of an internal network from the outside world. Virtual Private Network (VPN) connections using the IPSec standards can be made with the Cisco Secure PIX Firewall. The Cisco Secure PIX Firewall enforces secure access between an internal network and an intranet, extranet links, and the Internet.
CyberGuard Firewall for Unixware (CyberGuard)	An integrated security system with the highest level of protection and performance to shield your corporate data. Featuring a trusted operating system, CyberGuard has hardened the operating system to include Multiple Virtual Secure Environments (MVSE). MVSE uniquely controls access to system objects (files, directories, sockets, processes), and subjects (users, processes) . It offers the most comprehensive level of security on a variety of industry-standard Intel platforms, protecting your system from today’s sophisticated hackers.
Cyberoam (Elitecore Technolgies)	Cyberoam's user identity-based bandwidth management prevents bandwidth abuse and pipeline choking through bandwidth control and scheduling and offers committed, burstable bandwidth. Cyberoam CR100i, CR250i, CR500i are Gateway Security Appliances, offering comprehensive security to small and medium enterprises (SMEs) as well as branch offices against a range of internal and external threats, including viruses, worms, Trojans, spyware, phishing, pharming, DoS attacks, loss of confidential information and more. These all-in-one solutions offer comprehensive network protection with the entire suite of security features - identity-based firewall, VPN, anti-virus, anti-spam, intrusion detection and prevention (IDP), content filtering, in addition to bandwidth management and multiple link management over a single, easy-to-manage security appliance.
SonicWALL PRO (SonicWALL)	Provides Internet security, Virtual Private Networking (VPN), and content filtering with high performance hardware to meet the needs of large networks. SonicWALL PRO offers branch offices and large, single-site networks a comprehensive security system to combat intruders and secure important business data.  SonicWALL PRO is platform independent, easy-to-install and requires no security or networking expertise. Once installed, it runs quietly and can be securely managed via Web browser.
SonicWALL DMZ (SonicWALL)	Protects Internet-connected businesses from hackers and intruders, preventing theft, destruction, and manipulation of critical business data. SonicWALL also prevents employees from accessing objectionable Web sites and newsgroups through content filtering. Additional features include logging and reporting as well as IP address management. SonicWALL is the first security appliance for small to mid-sized businesses needing a secure, affordable, and easy-to-administer solution to protect against Internet intruders.
SonicWALL SOHO (SonicWALL)	Protects Internet-connected businesses from hackers and intruders, preventing theft, destruction, and manipulation of critical business data. The SonicWALL product also prevents employees from accessing objectionable Web sites and newsgroups through content filtering. Additional features include logging and reporting as well as IP address management. SonicWALL is the first security appliance for small to mid-sized businesses needing a secure, affordable, and easy-to-administer solution to protect against Internet intruders.

Note: - there are many more firewall vendors and here is only few vendors. Today SonicWall NAS series available in the Market.

What is Soncwall?

   

 

SonicWALLs are full-featured Internet security appliances, field-proven, third party certified solutions that meet the needs of any size organization with a direct connection to the Internet. SonicWALL Internet security appliances use stateful packet inspection to protect the private LAN from hackers and vandals on the Internet and have been awarded the internationally accepted ICSA Firewall Certification. They maintain the highest level of security by automatically checking if firmware updates with protection against newly discovered hacker attacks are available. All firmware updates are free for the first 90 days or for the term of your support contract.

What firewall products and options are available from SonicWALL?

SonicWALL has a range of products that fit any sized organization, ranging from just a few users to thousands. Options include content filters, anti-virus solutions for Windows, virtual private networking (VPN), intrusion prevention, gateway antivirus, anti-spyware, extended warranties, premium support, and more.

Why do we need a firewall?

With the increasing number of denial of service attacks, hacking attempts, viruses, worms, and spyware on the internet, any organization with a direct connection to the internet has a need for protection. Attacks from the internet can degrade your network performance. Activities such as the printing and file sharing between computers are affected, even though you are not "accessing" the Internet. Hackers can also exploit unsecure computers on your network to amplify their attacks if you are not protected. This means that a hacker can literally take control of a computer on your network and use it to add strength to an attack on other systems.

In addition to the prevention of attacks, one of the most commonly added options to the SonicWALL is the content filter. This is a firewall based filter and does not require any changes at the individual workstations for it to work. It is fully configurable and customizable. In addition, on December 21, 2000, Congress approved a law that makes Internet filtering a federal mandate for school computers with Internet access, applying to K-12 schools receiving E-rate discounts and other federal technology grants. The SonicWALL content filter makes implementation of this mandate a very easy task.

What are other reasons to buy a SonicWALL?

These internet security appliances have been very good quality and provide many excellent features. SonicWALL is continually updating their products to provide new features at no charge to owners of their products. For schools, the academic pricing has made the cost of protecting your network and servers even more affordable. With an excellent feature set that improves with each new release, and internationally accepted ICSA Firewall Certification.

support:- http://www.sonicwall.com