1. Networking Devices

2. Hubs Layer 1 device Repeats signal Single Broadcast Domain
Single Collision Domain
Forwards bits out all ports except the received
Less than $30 not often a solution

3. Bridges Layer 2 Builds a Learning Table using MAC addresses
Software-based decisions are standard which is slower than Switching
Low port density
Around $50 not often a solution

4. Switches Layer 2 Single Broadcast Domain
Each port is a Collision Domain
Builds a MAC or CAM table and forwards out destination port
Frames are created and forwarded at this layer
ASICs (Application-Specific Integrated Circuits) hardware decisions for speed
Options are line card (Layer 3), Modular or fixed (SFPs), White Box or Common Vedor
Access or Distribution. $100 - $10,000+

5. Routers Layer 3 Each port is a Broadcast Domain
Forwards Packets between Networks using IP addresses
Uses Routing Protocols and Static Routes to build Routing Tables
Options are line card (40Gb current cross-connects), QSFPs are $400+,
Core, Branch, Campus or Service provider. $100 - $20,000+

6. Wireless AP
Layer 2
Shared Bandwidth (Full-Duplex “like” with dual antennas)
2.4 and 5.0 GHz common
Channels 1,6 and 11 do not overlap and can assist with interference caused by wireless phones etc.
Avoidance must be used (CSMA/CD for wired vs CSMA/CA for wireless)
Commonly built into Home modem/gateway. $50 - $200

7. Gateway Connects LAN to Service Provider
Firewall and Proxy capabilities
Performs NAT
Home gateways perform NAT, Firewalls, can separate the DMZ, Port- forwarding. Cost $50 - $200
Data Center gateways are high capacity routers capable of 40Gb or 100Gb cross-connects to the ISP. High capacity backbone routers such as Cisco Cost depends on line cards and modular-pluggable chosen. $2,000 - $20,000++

8. Firewall
Can operate at any layer depending on how security is implemented
Monitors/Filters incoming traffic
Designed to protect devices
Packet inspection, Packet filtering and Application firewalls are common
Vendors Palo Alto, Checkpoint, F5 and Cisco
Depends on vendor capabilities and options. $200 - $20,000