Firewall

Content:

Firewall or Firewall

The firewall is an installation program that acts as a filter, blocking or allowing certain connections and data transmissions to or from the Internet, that is, it acts as a barrier between the network and our PC. To understand this definition we can observe the figure.

firewall

As its translation says, it is nothing more than a firewall, a meaning adapted from the terminology of the fire services, which have a special technique to control fires of great intensity and prevent their spread. A firewall in computing is very similar because it allows control of unwanted access through security policies that can be defined by the user, both locally and by providing network services. For this, there are two types of Firewall applications: 

  • Those intended for individual users,
  •  And those designed for companies and to be installed in proxies (computers that serve as a connection point for others connected to the network).

Why use a firewall?

The purpose of network firewalls is to keep intruders out of the reach of one's own jobs. Frequently, a network firewall can act as an ambassador company for the Internet. Many companies use their firewall system as a place to store public information about company products, files that can be retrieved by company personnel, and other information of interest to company members.

Many of these systems have become important parts of the Internet service structure (examples found include: UUnet.uu.net, whitehouse.gov, gatekeeper.dec.com).

What can a firewall protect against?

Some firewalls only allow mail traffic through them, so they protect against any attack on the network other than an email service.

Other firewalls provide fewer restrictions and block services that are known for their constant intrusion problems. Firewalls are generally configured to protect against unauthorized interactive logins from anywhere in the world.

This mainly helps to prevent acts of vandalism in machines and software of our network. More elaborate network firewalls block traffic from outside to inside, allowing inside users to communicate freely with outside users. Firewall networks can protect us from any type of network attack, as long as they are configured for it. Firewall networks are also a good security system when it comes to controlling statistics of users who tried to connect and were unsuccessful, traffic that went through it, etc... This provides a very comfortable system for auditing the network.

Recommendations

  • Always keep in mind the issue of security, until it is something innate in your behavior when connecting to the Internet. Do not abandon it out of laziness. It is the biggest source of problems.
  • Periodically check the level of security with which you are connected (port scan, antivirus, firewall, sensitive data in account settings...)
  • Periodically back up your data.
  • If you use connections with Flat Rate (ADSL and CABLE, since we still don't have FLAT RATE for RTB) turn off the PC when you don't use the connection. You will also save energy :-)
  • If you use RTB, check the Telephone Access to Networks from time to time to see the connection and be careful with some pages, especially sex, that create by themselves, or ask you to install, a new
  •  Telephone Access to Networks with a PAYMENT telephone number (type 906)
  • Be especially careful when downloading software from questionable sites.
  • If you use Server programs for the Internet, be attentive to the updates of the programs because they will surely fix security holes.
  • Install and always have an Antivirus active and, of course, update it periodically.
  • Install a firewall and keep an eye out for updates.
  • In principle, configure any program, and especially the Internet browser, at the highest level of security that it allows. When necessary, you can always lower the security level and return it to its maximum level when you no longer need it.
  • Do not trust the links (links) of the pages. Check that you are taken to the real page where you want to go.
  • On web pages where you have to enter sensitive information (for example, the credit card number), make sure that they are always secure (they start with https:)
  • Configure your mail client to receive and send mail in text mode. In addition to the fact that html almost never contributes anything, it is a source of security and privacy problems.
  • NEVER execute an email attachment with double click, even if it was sent to you by your best friend.
  •  It is always better to save the attachment, and first run the program that "should" open that attachment and from that program open the file.
  • Don't spread HOAXs. YES, dare!!! to break the chains of messages. They act like a VIRUS since you yourself are the propagator.
  • If you do not want to receive SPAM, when you send a message to the NEWS, put both in the email address of the message header and in the signature some identifier that makes it impossible for it to be collected automatically by computer programs. For example name@QUITAESTOdomain.com, name@domainESTONOVALE.com. ALWAYS do it to the right of the at sign and NEVER in the name.
  • Encrypt your most sensitive messages and files.
  • Never accept files that you have not requested when you are in chat (IRC) or newsgroups (NEWS).