Firewalls Explained

You know that firewalls play an integral part in computer security. But when it comes down to it, do you really know what they are and how they operate?

Firewalls essentially act to protect networks and keep watch on incoming and outgoing data. Most can be classified into three distinct types: packet filter firewalls, application proxy firewalls and packet inspection firewalls.

The first type is a router-based and no longer used. Packet filter firewalls work by comparing the source and destination IP address and port numbers with predefined access control rules. If these details all match, the information packet is passed along. If not, the packet is discarded or terminated.

Application proxy firewalls eventually took the place of packet filter firewalls, which allowed direct connection between trusted and undressed and systems. This later generation of firewall works by checking which service is running on port for which an information packet is destined. If that service is running, the packet is permitted entry. Otherwise, it is eliminated. Once this is done, the firewall extracts the data and sends it along to the appropriate service.

Packet inspection firewalls are similar to packet filter ones. Rather than simply verifying the source and destination IPs and ports, however, it also verifies the content of the data before allowing it to pass. The two ways it inspects the data through analyzing state and session.

Firewalls can generally be configured by adding one or more filter(s) to server ports, which can be likened to “virtual doors” extant on a server and through which services are made available. If a server is available for public use, these “doors” are open. If not, they are blocked via a firewall. Filters can also be added to domain names: most typically, they are used to block websites access in schools, offices and homes.

Austin Mobile Computer Repair can help protect your computers from unwanted outside access. Whether you have questions or issues about firewalls or are in need of the speediest, most efficient computer repair service in Austin, we’re there when you need us most. Call us today!

Call Austin Mobile Computer Repair at (512) 872-2811.

Contact Us




Chelsey Jenkins
Read More
"Ryan was fast and professional. He knew the problem immediately and was able to fix it same day. I would highly recommend him!"
Roberta Cohen
Read More
"I highly recommend Ryan. He knows his stuff and is very professional! He is my 'go to' computer person now!"
Don Hurst
Read More
"Austin Mobile Computer Repair provides excellent service in a timely manner. They are efficient, knowledgeable and very customer friendly. I highly recommend Austin Moblie Computer for fixing computer issues."
William Roberts
Read More
"Ryan got back to us very quickly and was very knowledgeable and patient with our problems, and got the issue fixed better than we could have hoped for."
Read More
"Very informative and highly recommend if you're ever having problems with anything."
Stephanie Lucie
Read More
"Tommie came out to our house, was timely, responsive and addressed our computer issues. I'll be calling again!"
Austin managed IT services coupon