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Hub. Connects multiple Ethernet devices together into a single network segment Each port acts as both input and output where every input becomes the output for every other port. OSI layer 1 device (Physical layer)
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Hub • Connects multiple Ethernet devices together into a single network segment • Each port acts as both input and output where every input becomes the output for every other port. • OSI layer 1 device (Physical layer) • Made mostly obsolete by Network switches but still has niche uses such as inserting a protocol analyzer into a network. • Slightly more fool proof than switches in that switching loops aren’t as much of an issue • Hubs can be used to connect legacy devices to modern networks • $20-90
Switch • Device that links network segments or devices. • Route data at the Data Link Layer (OSI 2). • Switches may also process data and operate on OSI layer 3. • Receives message from any connected device and transmits the message only to the intended recipient(s). • Typically used in larger networks • Primary building block of LANs • $30-2000
Router • Forward data packets between networks • Operates on OSI Layer 3 and Layer 2 • Packets are checked against the routing table to determine destination and then encapsulated and sent using Layer 2 • Contain firmware for different network protocols • Used in networks of all sizes from enterprise to home • May be used to connect together various networks to form subnets • $20-200
Bridge • A network bridge is the combining of 2 or more networks to create an aggregate network. • OSI Layer 1 and 2 (works entirely beneath Network Layer) • 4 types: Simple, multiport, learning/transparent and source route. All serve a different purpose • The purpose is purely for combining networks to make larger networks • $40-250
Gateway • Gateways server as a network node designed to communicate with another network that might be using a different protocol. • Can translate protocols, match impedances, convert rates and translate signals. • Operate at any network layer. • Allows users to communicate with servers and send IP packets to networks outside a given subnet mask. • A gateway is a key component of a router but other devices, such as PCs, can function as a gateway. • $100-1000
Firewall • Firewalls are devices (or software) that control incoming and outgoing traffic based on a set of rules • Essentially, it is a barrier for computers and networks from malicious (not necessarily) content • The primary use is security on a network of any size though hardware firewalls are a bit more expensive and more practical for a large business • Many free firewalls available software wise, some with subscriptions, others with one time prices between $15-70 • Hardware firewall $100-23,000 (Barracuda Spam and Virus Firewall 800 is very expensive!)
Wireless AP • Wireless Access Points let devices connect to a wired network using Wi-Fi or a similar standard. • Typically a WAP is included as part of a router. • Myriad of applications from personal wireless networks to public access points • Various kinds of wireless standards but IEEE 802.11 are the most common • $30-1000
Sources • Hub picture - http://en.wikipedia.org/wiki/File:4_port_netgear_ethernet_hub.jpg • Switch picture - http://en.wikipedia.org/wiki/File:2550T-PWR-Front.jpg • Router picture - http://en.wikipedia.org/wiki/File:Adsl_connections.jpg • Bridge picture - http://3.bp.blogspot.com/--QHFyMSnwnM/T6P9dt1r8II/AAAAAAAAAF0/L4B_gqWabfo/s1600/bridge.jpg • Gateway picture - http://en.wikipedia.org/wiki/File:Juniper_srx210_front_view.jpg • Firewall picture - http://media.cablesandkits.com/ipn/ASA5505BUNK9a_300.jpg • WAP picture - http://en.wikipedia.org/wiki/File:Linksys_WAP54G.JPG