Network Devices
Hub
- OSI Level 2, Data Link
- Receive frame from a host on one port, transmit on every other port
- create collision domain
Bridge
- connect two hub networks into one.
- uses mac address filtering to only send frames between hubs if the sending and receiving hosts are connected to different hubs.
- Allows a larger hub network while decreasing collisions.
Switch
- Exist in OSI layer 2, Data Link
- Keeps a Source Address Table, maps the MAC address of a host to the port it is attached to.
- only sends frames to the port where the destination MAC address is attached.
- Collisions occur significantly less frequently than a hub network
- If a frame has an unknown MAC address then it is sent to all hosts.
Managed Switch
A network switch that offers lots of configuration options. These can be:
- Bandwidth per port
- Duplex setting per port
- etc
Multi-Layer Switch
A switch that also operates as a router. That means it has both a broadcast domain, but can route layer 3 packets based on IP address, too. Some things that multi-layer switches can do:
- Load-balancing
- Traffic shaping
- Port bonding (combining multiple ports to increase bandwidth)
- Can run Intrusion Detection Systems
- Port mirroring (sending identical data out two ports)
- Port authentication
Multiplexer
- Commbines multiple connections and puts them into a single connection type.
- Can be used to combine many host connections into one long distance wire.
- Used in circuit switch networks
Repetears and Amplifiers
An amplifier takes a signal and increases it. It can theoretically be used on both digital and analog signals, but in practice is only used on the later. A repeater works only on digital signals. It can interpret the signal, recreate the original data being carried, and send a new, cleaner signal.
Modulator and Demodulator
Transceiver
a modular network device designed to provide a seamless link between different types of network interfaces (e.g. copper and fiber, or vice versa)
Gigabit Interface Converter (GBIC)
- Modular (hot swappable) interface
- Converts optical signals to electrical signals (and visa-versa)
- Data transfer of 1 Gbps
- Small form factor transceiver
- Newer transceiver type that replaces GBIC
- Hot swappable
- Transmission rate of 1 Gbps
- Commonly used in 10GBase networks
- Transmission rate of 16 Gbps