Firewall between LAN and WAN

This computer security diagram example was designed on the base of the Wikimedia Commons file: Firewall.png.
[commons.wikimedia.org/ wiki/ File:Firewall.png]
This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license. [creativecommons.org/ licenses/ by-sa/ 3.0/ deed.en]
"In computing, a firewall is a network security system that monitors and controls the incoming and outgoing network traffic based on predetermined security rules. A firewall typically establishes a barrier between a trusted, secure internal network and another outside network, such as the Internet, that is assumed to not be secure or trusted. Firewalls are often categorized as either network firewalls or host-based firewalls. Network firewalls are a software appliance running on general purpose hardware or hardware-based firewall computer appliances that filter traffic between two or more networks. Host-based firewalls provide a layer of software on one host that controls network traffic in and out of that single machine. Firewall appliances may also offer other functionality to the internal network they protect such as acting as a DHCP or VPN server for that network." [Firewall (computing). Wikipedia]
The cybersecurity diagram example "Firewall between LAN and WAN" was created using the ConceprDraw PRO software extended with the Network Security Diagrams solution from the Computer and Neworks area of ConceptDraw Solution Park.

"Fault-tolerant computer systems are systems designed around the concepts of fault tolerance. In essence, they have to be able to keep working to a level of satisfaction in the presence of faults. ...
Most fault-tolerant computer systems are designed to be able to handle several possible failures, including hardware-related faults such as hard disk failures, input or output device failures, or other temporary or permanent failures; software bugs and errors; interface errors between the hardware and software, including driver failures; operator errors, such as erroneous keystrokes, bad command sequences, or installing unexpected software; and physical damage or other flaws introduced to the system from an outside source." [Fault-tolerant computer system. Wikipedia]
The computer network diagram example "Cisco LAN fault-tolerance system" was created using the ConceptDraw PRO diagramming and vector drawing software extended with the Cisco Network Diagrams solution from the Computer and Networks area of ConceptDraw Solution Park.

"At different scales diagrams may represent various levels of network granularity. At the LAN level, individual nodes may represent individual physical devices, such as hubs or file servers, while at the WAN level, individual nodes may represent entire cities. In addition, when the scope of a diagram crosses the common LAN/ MAN/ WAN boundaries, representative hypothetical devices may be depicted instead of showing all actually existing nodes. For example, if a network appliance is intended to be connected through the Internet to many end-user mobile devices, only a single such device may be depicted for the purposes of showing the general relationship between the appliance and any such device." [Computer network diagram. Wikipedia]
The physical LAN and WAN diagram template for the ConceptDraw PRO diagramming and vector drawing software is included in the Computer and Networks solution from the Computer and Networks area of ConceptDraw Solution Park.