Networking devices are used to connect multiple device or computers to share the information, also called communication devices.
Switch: Switch is a centralize networking device where all the hosts get connected in a network. Switches are work on Layer 2 (Data-Link Layer). Switches support broadcast domain. Each port creates a collision domain in a switch.
Switches work on mac address and create a mac table when data is transferred from one host to another host. We understand from an example, suppose we have implemented a new switch in a network, first time a packet received on a port, initially it will do broadcast to all port (it means switch will send this packet to all other connected port). The second time it does Unicast or multicast as needed. Switches store Source Mac Address when a host sends a packet.
Switches are work on the Layer 2 of OSI model and some of also working on Layer 3 called L3 switches. L3 switches do routing and perform the functions of Layer 3(Network Layer)
Manageable Switch: In this, we can create a VLAN. Manageable also enable some features like STP (Spanning Tree Protocol), QoS, set port speed, and can also provide security to each port. The manageable switch also supports SNMP, which allows monitoring the traffic.
Non-Manageable Switch: These are plug and play switch. There is no console to configure.
Router: Router is a networking device which used to connected two different networks. Router is also providing the best path to travel a packet from source address to destination. Router also called WAN device or we can say it used to provide a WAN connection.
Router maintains a table called Routing Table where it stores information like destination address, Next hop address, Metric value, Routes, and Interface.
Router works on Layer 3 of OSI model and the data transmission form is Packets. Router has 2/4/8 ports.
Router Component and boot process, you can read in our post: Router Component and Boot process
Firewall: Firewall is a networking device which protects our network and filters our traffic according to our policies. Firewall protect our internal network from external unauthorized access.
A firewall can be a hardware or software devices. A firewall can perform many operations like NAT, Packet Filtering, Routing, can report network traffic activities, VPN configuration much more.
Types of Firewall:
- Packet Filtering Firewall
- Stateful Firewall
- Application or Proxy firewall
- Circuit Level Firewall
We will discuss a firewall more deeply in another post.
Access Point: Access Point is a hardware device which use to create a WIFi (Wireless Fidelity) and using WIFI, a host or device can be connected to the wired connection/the internet.
Access point work like a transmitter and receiver for Radio frequency signals.
Wireless Controller: WLC is a centralized device to manage Access Point and provide user interface and CLI (command line interface) to manage.
Why require WLC (Wireless Controller):
- Reduce the interference
- Radio Frequency management (RF Channel)
- Seamless Roaming
- Radio Balancing
- Quality of Service (QoS)
- Allow or block traffic/port in network
- Load Balancing: It will do the load balancing, if load on one access point is high then it will adjust the users to nearest low load access point.
- Fail Over: If an access point falls down then WLC will shift the users to the nearest access point that is redundancy while in the standalone configuration of Access point, it will drop the users.
Wireless control encrypts a packet using 128-bit encryption technology. WLC also provide security to block/allow like Rouge Access Point detection, Denial of service attack (DOS), Ad-Hoc Network.