Network Definition
A network is a group of two or more computers or other electronic devices that are interconnected for the purpose of exchanging data and sharing resources.
Network Types
Local Area Network
LANs connect groups of computers together across short distances (within a building or between a group of two or three buildings in close proximity to each other) to share information and resources.
Enterprises typically manage and maintain LANs
Campus Area Network (CAN)
Larger than LANs, but smaller than metropolitan MAN
these types of networks are typically seen in universities
can be spread across several buildings that are fairly close to each other so users can share resources.
Metropolitan Area Network (MAN)
These types of networks are larger than LANs but smaller than WANs
Ownership and maintenance are handled by ISP internet service providers
Wide Area Network (WAN)
Slightly more complex than a LAN, a WAN connects computers together across longer physical distances. This allows computers to be remotely connected to each other over one large network to communicate even when they’re miles apart.
The Internet is the most basic example of a WAN, connecting all computers together around the world. Because of a WAN’s vast reach, it is typically owned and maintained by multiple administrators or the public.
Netwok Component
End Device
Every computer on a network is called a host or end device. End Devices Servers are computers that provide information to end devices:
•email servers
•web servers
•file server Clients are computers that send requests to the servers to retrieve information:
•web page from a web server
•email from an email server
Intermediary Network Devices
An intermediary device interconnects end devices. Examples include switches, wireless access points, routers, and firewalls. Management of data as it flows through a network is also the role of an intermediary device, including:
•Regenerate and retransmit data signals.
•Maintain information about what pathways exist in the network.
•Notify other devices of errors and communication failures
Network Media
•Metal wires within cables Uses electrical impulses
•Glass or plastic fibers within cables (fiber-optic cable) Uses pulses of light.
•Wireless transmission Uses modulation of specific frequencies of electromagnetic waves.
Reliable Networks
A fault tolerant
network limits the impact of a failure by limiting the number of affected devices. Multiple paths are required for fault tolerance.
scalable network
A scalable network can expand quickly and easily to support new users and applications without impacting the performance of services to existing users.
.
Quality of Service (QoS)
is the primary mechanism used to ensure reliable delivery of content for all users. With a QoS policy in place, the router can more easily manage the flow of data and voice traffic.
Network infrastructure security
•Physical security of network devices
•Preventing unauthorized access to the devices •Information Security
•Protection of the information or data transmitted over the network
interface g0/0
no shutdown
ip address 192.168.1.1 255.255.255.0
interface g0/1
no shutdown
ip address 209.165.200.1 255.255.255.0