CompTIA Network+ 

Network Devices

Hub
• An OSI layer 1 device
• Multi-port repeater
• Everything is half-duplex
• Becomes less efficient as speeds increase

 

 

Switch
• An OSI layer 2 device
• Hardware bridging ASICs (very fast!)
• Forwards traffic based on MAC address
• The core of an enterprise network
• High bandwidth - Many simultaneous

Router
• An OSI layer 3 device
• Routes traffic between IP subnets
• Routers inside of switches are sometimes called “layer 3 switches”
• Layer 2 = Switch, Layer 3 = Router
• Often connects diverse network types - LAN, WAN, copper, fiber

Modem

• Modulator / Demodulator
• Uses standard phone lines
• POTS modems now used for
• backup and utility functions

 

Firewall
• OSI layer 4 (TCP/UDP), some firewalls filter through OSI layer 7
• Filters traffic by port number
• Can encrypt traffic into/out of the network and between sites
• Can proxy traffic - A common security technique
• Most firewalls can be layer 3 devices (routers

 

Wireless Access Point

• OSI layer 2 device
• Not a wireless router
• A WAP is a bridge - makes forwarding decisions based on MAC address

 

Intrusion detection/prevention system


• Protects against OS and application exploits
• Detection - alerts but does not stop the attack
• Prevention - blocks the attack
• Network-based - high-speed appliances
• Host-based - runs on your operating system

 

Content Filters
• Control traffic based on network data
• Filter email - avoid malicious software, phishing, and viruses
• Filter URLs - filter by web site category

 Practice CompTIA EXAM

JoomShaper