Module 4, L2 Network Devices

Module 4 Network Devices

By Mrs Cauldwell

Devices equipped to carry electrical power on the same cable as Internet signals

​

Wired Connection​

​Power Over Ethernet

•SOHO Internet router/modems

•Multifunction appliances combining several networking devices

•Switch—connects 4 or 8 computers together in an Ethernet LAN using RJ-45 network ports and twisted-pair cabling

•Access Point (AP)—creates a Wi-Fi wireless network (WLAN) between computers and mobile devices equipped with suitable adapters and also switches communications between the wired and wireless networks

•Internet router/modem—connects the wired and wireless network clients to the Internet via a WAN link

​

​SOHO- multifunction device

• generally includes a switch, a firewall, and a DHCP server

• a router needs to essentially be a small computer, complete with CPU, memory, storage, and operating system meaning it needs a user interface

• When first installed, there will be a default username and password​

​SOHO- router

Connects two different networks together- directs traffic according to IP addresses

​

Hub, Bridge, Switch connect DEVICES ​

​Router

​

​These devices are often simply referred to as "routers."

​

It is possible for the modem and the router to be separate appliances.

​

The function of the modem is to transmit frames across the WAN link, while the function of the router is to forward packets between the local network and the Internet.

​

Modem- modulate/demodulate​

​SOHO- multifunction device

Access Point

In computer networking, a wireless access point, or more generally just access point, is a networking hardware device that allows other Wi-Fi devices to connect to a wired network.

Configuring an Access Point

•Connect to admin interface via IP address

•Log in using admin credentials–change the password!

You must always change the default password (typically "default," "password," or "admin") to prevent unauthorized access.​

•Configuration settings

•Service Set ID (SSID)

•Wireless mode/compatibility mode

Used to create Wireless networks​

Access Point

​Controls incoming and outgoing traffic; filters good and bad traffic based on polices and rules

​Firewall

A hub connects devices within a network.

​

When data comes in, hubs send data to all other ports. Data collided​

​

Does not read protocols or addresses. Sends information blindly​

​

hubs= dumb​

​

Using a hub

Since traffic is directed to the correct node, most switches are also able to send and receive data at the same time.

​

Smart Switch

​

Replaced Hubs​

​

Directs traffic according to MAC addresses- 4 ports​

​

Switch

Similar to a hub, but sends data to the correct nodes not ALL nodes blindly

​

Connects devices; traffic is directed and sent via MAC addresses

​

Not used as often

​

​

​Bridge

While the switches and access points can provide thousands of ports and network connections, it is inefficient to have that many connections to the same "logical" network. The ports are divided into groups using a technology called Virtual LAN (VLAN) and each VLAN is associated with a different subnet. Communications between different VLANs have to go through a router.

​ networks divided through software to operate like they are operating on physically separate hardware

Virtual LAN

IDSes, like they sound, are used only to detect suspicious activity and alert administrators of potential issues

Intrustion Detection Systems

IPSes are used to prevent threats and can block traffic, disconnect users, or take other actions against a potential attack.

Intrusion Prevention System