A machine that acts as the central relay between computers on a network Low cost, low function machine usually operating at Layer 1 Ties together the computer attached to it through multiple ports Acts as a repeater Approx. cost = $10 to $1300

HUB

Relays traffic by using a Layer 2 address (i.e. Ethernet MAC address or ATM/MPLS label) Contains software to support building routing tables Improves network traffic Improvement over the HUB Approx. cost = $20 to $79k

SWITCH

Flexible and powerful machines Operate at an OSI Layer 3 with an IP address Some contain extensive network management features Various models can be setup as a FIREWALL More powerful than the HUB, SWITCH or BRIDGE Approx. cost = $30 to $300

ROUTER

Very similar to the SWITCH Operate at Layer 2 Associated with LAN devices Only operates using an Ethernet MAC address for routing Slight improvement over the HUB Approx. cost = $10 to $150

BRIDGE COLLISION DOMAIN

Connected to 2 separate networks with different protocols Serves as the access point on one network for another network Operate at OSI Layer 3 Commonly connects an internal network and an external network Approx. cost = $90 to $1800

GATEWAY REMOTE CLIENT CORPORATE SERVER

Used to help secure a network Usually placed between a secure internal network and an unsecured external network Can be hardware based or software based Monitors incoming and outgoing traffic Allows or blocks traffic based on setup Approx. cost = $75 to $100k

FIREWALL

Commonly referred to as a WAP Connects to one or more devices wirelessly Allows for devices to be located in the general area of the WAP with no required wires Allows connected devices to connect to a wired network Some standards are WiFi and Bluetooth Approx. cost = $13 - $3000

WIRELESS AP

HUB WAP SWITCH ROUTER FIREWALL GATEEWAY BRIDGE