Network Devices and Technologies
The Security+ Certification exam requires knowledge of networking and a thorough understanding of security concepts that apply to network technologies. A Network+ certification and/or a solid background and experience in networking is recommended.
Security+ Objective 1.1 covers security configurations of network devices and other technologies.
Network Devices
Firewall:
A Firewall is a network device that monitors and controls incoming and outgoing network traffic. A firewall establishes a network traffic barrier between a trusted internal network, and an outside network. Example: a firewall would control traffic between a trusted internal Local Area Network (LAN) and an outside network like the Internet. A firewall filters traffic based on rules placed on the firewall which control what traffic is allowed, or not allowed, to enter or leave the protected network. Typically, firewalls are configured with a deny-all rule that states all traffic is denied unless another rule exists that allows that specific traffic. Access Rules can be specified for both inbound and outbound traffic.
Routers:
A Router is a network device that performs routing, or sending, data from one network to another network. A router is a layer-3 device of the Open Systems Interconnection (OSI) model and it normally connects at least two networks, commonly two LANs or WANs, or, a LAN and an Internet Service Provider (ISP) network. Routers use headers and forwarding tables to determine the best path for forwarding packets. Routers can be used to create network boundaries known as broadcast domains. A broadcast domain is a group of systems that can receive one another’s broadcast messages. Instead of a device broadcasting messages across entire networks, a broadcast domain limits broadcast messages to just the devices within its broadcast domain.
Quick Definitions:
- Firewall: A network device that monitors and controls incoming and outgoing network traffic between a trusted internal network and another network..
- Router: A network device that performs routing, or sending, data from one network to another network. Connects (2) or more networks together and routes traffic between them.
References
Webopedia ISP
Webopedia OSI
Webopedia Router
Wikipedia Firewalls
Wikipedia LAN
