ALERT

[FREE DEMO] Deploy Your Enterprise Cloud in Minutes

Firewall

Definition - What does Firewall mean?

A firewall is software used to maintain the security of a private network. Firewalls block unauthorized access to or from private networks and are often employed to prevent unauthorized Web users or illicit software from gaining access to private networks connected to the Internet. A firewall may be implemented using hardware, software, or a combination of both.

A firewall is recognized as the first line of defense in securing sensitive information. For better safety, the data can be encrypted.

Techopedia explains Firewall

Firewalls generally use two or more of the following methods:

  • Packet Filtering: Firewalls filter packets that attempt to enter or leave a network and either accept or reject them depending on the predefined set of filter rules.
  • Application Gateway: The application gateway technique employs security methods applied to certain applications such as Telnet and File Transfer Protocol servers.
  • Circuit-Level Gateway: A circuit-level gateway applies these methods when a connection such as Transmission Control Protocol is established and packets start to move.
  • Proxy Servers: Proxy servers can mask real network addresses and intercept every message that enters or leaves a network.
  • Stateful Inspection or Dynamic Packet Filtering: This method compares not just the header information, but also a packet’s most important inbound and outbound data parts. These are then compared to a trusted information database for characteristic matches. This determines whether the information is authorized to cross the firewall into the network.

Techopedia Deals

Connect with us

Techopedia on Linkedin
Techopedia on Linkedin
Tweat cdn.techopedia.com
"Techopedia" on Twitter


'@Techopedia'
Sign up for Techopedia's Free Newsletter!

Email Newsletter

Join thousands of others with our weekly newsletter

Resources
The 4th Era of IT Infrastructure: Superconverged Systems
The 4th Era of IT Infrastructure: Superconverged Systems:
Learn the benefits and limitations of the 3 generations of IT infrastructure – siloed, converged and hyperconverged – and discover how the 4th...
Approaches and Benefits of Network Virtualization
Approaches and Benefits of Network Virtualization:
Businesses today aspire to achieve a software-defined datacenter (SDDC) to enhance business agility and reduce operational complexity. However, the...
Free E-Book: Public Cloud Guide
Free E-Book: Public Cloud Guide:
This white paper is for leaders of Operations, Engineering, or Infrastructure teams who are creating or executing an IT roadmap.
Free Tool: Virtual Health Monitor
Free Tool: Virtual Health Monitor:
Virtual Health Monitor is a free virtualization monitoring and reporting tool for VMware, Hyper-V, RHEV, and XenServer environments.
Free 30 Day Trial – Turbonomic
Free 30 Day Trial – Turbonomic:
Turbonomic delivers an autonomic platform where virtual and cloud environments self-manage in real-time to assure application performance.