Firewalls protect a Network of Computers from being Compromised, Denial of Service and other Attacks from Hackers trying to Intrude the network from outside. A Firewall can be in the form of a Hardware or a Software on a Computer, as well. A Firewall needs to be connected to a minimum of two Network Interfaces, one which is supposed to be protected (Your Internal Network) and other which is Exposed to Attacks (Generally Internet). A Firewall can also be considered as a Gateway deployed between the two Networks.
firewall is divided in two type :
1. Hardware base firewall.(Cisco sonicwall checkpoint sonicwall checkpoint,Fortinet juniper)
hardware firewalls will have a minimum of four network ports to connect other computers, but for larger networks, business networking firewall solutions are available. A hardware firewall uses packet filtering to examine the header of a packet to determine its source and destination.
2. Software base firewall(window Firewall, ISA/TMG,Pfsense)
A firewall is a system designed to prevent unauthorized access to or from a private network. You can implement a firewall in either hardware or software form, or a combination of both. Firewalls prevent unauthorized internet users from accessing private networks connected to the internet, especially intranets.
Window Firewall:
Default Behavior:
1.Allow all Outbound(Outgoing) Traffic.
2.Deny all incoming(inbound) Traffic.
State Full Firewall:
Maintain Record of traffic in state Table.
LAB (Play with firewall Rules)
1.Allow Ping/ICMP :
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| Add Rule |
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| Click Custom Rule and Click Next |
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| Click All Program and Click Next |
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Select Protocol Type ICMPv4 And Click Next
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| Select The Profile And Click Next |
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| Click Rule Name And Click On Finish |
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| Click On Port And Next |
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| Select The Protocol And Port Then Click Next |
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| Click Allow The Connection And Click Next |
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| Select Profile And Click Next |
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| Click The Rule Name And Click On Finish |
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| Add caption |
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| Select Port Rule And Click On Next |
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| Select Protocol And Port then Click On Next |
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| Click On Block the Connection And Click On Next |
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| Select The Profile And Click On Next |
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| Click Rule Name And Click On Finish |
5.Block Google Chome/firefox Program.
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| Create New Rule |
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| Click On Program and Click Next |
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| Select The Program Path And Click Next |
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| Click Block The Connection And Click Next |
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| Select The Profile Then Click Next |
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| Click Rule Name then Click On Next |
Proxy Server:
A proxy server verifies and forwards incoming client requests to other servers for further communication. A proxy server is located between a client and a server.where it acts as an intermediary between the two, such as a Web browser and a Web server. The proxy server's most important role is providing security.
Types Of Proxy Server:
1.SSL Proxy:
SSL stands for Secure Sockets Layer and is a protocol which is used to protect your data during transmission. SSL is commonly used on the Internet when you execute a transaction and is symbolized by the padlock icon you typically see next to the URL address in the top of your browser window. It is also symbolized by https as opposed to http.
An SSL proxy server is connected between the client and the server to provide Secure Socket Layer support. SSL basically intervenes in the connection between the sender and the receiver which prevents hackers from attacking the network and intercepting personal or financial information which is being transmitted over the Internet.
2. FTP Proxy
FTP stands for File Transfer Protocol and is used in many different applications where you are uploading data to a server. A prime example of how FTP works is when you are building a website. In order to make the website visible to the world you must make a connection with the server space you reserved and then upload the website folders to the server to make the site live on the Internet.
An FTP proxy server in advanced mode will offer enhanced security for uploading files to another server. The server typically offers a cache function and encryption methods which make the transmission process secure and safe from hackers. In addition to relaying traffic in a safe environment an FTP server keeps track of all FTP traffic.
3.HTTP Proxy:
An HTTP proxy provides for the caching of web pages and files which allows you to access them faster. Most browsers utilize an HTTP proxy to cache websites you frequently visit so you can quickly access them without having to completely download the page all over again.
When you type in a URL for a website you want to access an HTTP proxy will search for the website address in the cache. If the website address is located it will return the website to you immediately as opposed to you having to wait for it to download.
The downside of an HTTP in some instances is that the cache can build up which slows down your browsing activity. To get around this you must send instructions to clear the cache to speed up your browsing activity. Additionally, an HTTP proxy is capable of filtering content from web pages and reformatting pages to suit the device you are using to access the page.
4.SOCKS Proxy:
SOCKS really stands for SOCKets and is different than a normal proxy since it is considered to be an application. When you compare a SOCKS proxy to an HTTP proxy, the HTTP proxy handles the request you send to access content on the Internet. On the other hand, when you contact a SOCKS proxy server the connection is established through the exchange of messages which establishes the proxy connection
The connection works through an Internet Protocol (IP) tunnel which also deploys a firewall. The SOCKS proxy requests originate from the firewall using SOCKS protocol and then the network (Internet) communicates with the SOCKS server request as if it were your own machine making the actual request to access a web page.
In order to use a SOCKS proxy your PC must have the capability to handle SOCKS protocol plus it is necessary to operate and maintain a SOCKS server. SOCKS technology was originally developed to access the Internet and its main features are the ability to bypass default routing on an LAN (Local Area Network) or internal network plus, it can provide authentication for protocols that you would otherwise be unable to access.
5.Anonymous Proxy:
An anonymous proxy is just as the name implies and provides you with privacy while you are browsing the Internet. It protects your privacy by hiding your IP (Internet Protocol) address from website owners, eavesdroppers, and other sources that exploit your identity by sending you targeted advertising based on your location or in the case of eavesdroppers, stealing your personal information and listening to your conversations.
An anonymous proxy is also capable of eliminating cookies which track your activity, popup advertisements which can be an annoyance as well as a danger to your PC, and other components that invade your privacy while you are surfing the Internet.
There are a number of anonymous proxy sites online which allow you to protect your identity while you surf the web. Some of them are free and others charge you a fee plus, you also have to be careful which ones you choose to use as some of them are ineffective and can harm your PC. Others provide a secure and safe way to browse the Web.
