So, basically all about networks.
Ang tanong, ano ba ang ibig sabihin ng network with regards sa computer networking na paga-aralan natin dito sa entirety ng CCNA study mo?
Pag sinabing network - yan ay interconnection ng mga devices (routers, switches, firewalls, access points, etc. ) at ng mga end devices ( PCs, network printers, servers) para makapag-communicate sila sa isa't isa.
Take note na ang isa sa mga pinaka-main functions bakit tayo nagne-networking ay para maka-pagshare ng mga resources.
Yang mga resources na yan can be:
Pag tayo ay nagne-networking, basically nagke-create tayo ng interconnection between end-users to servers and other hardware resources.
Ngayon, yung mga servers and hardware resources na yan can be located on-premise : ibig sabihin, yung end-user at yung mga hardware resources are located on the same location.
Or, yung mga servers and hardware resources can be located off-premise : ibig sabihin, yung mga hardware resources are located on a different location from the end-users.
Networking enables us to transfer data from one location to another. Bawat isang location is actually a type of environment - pwedeng home environment, a small business environment, or even large enterprises comprising of many types of sub-environments.
Eto yung ilan sa mga network environments na mae-encounter mo:
Eto yung smallest network environment.
Home Offices are obviously offices for individuals working from home na nangangailan ng access
to the internet para sa day-to-day job nila. Itong mga home offices na to can be connected thru VPN (Virtual Private Network) to access resources from their Main Office.
Ang mga small offices naman na pasok sa category ng SOHO are typically networks with less than 10 end-users. Take note na yung 10 end-users na yan ay categorically speaking lang. Small offices can actually have more than 10 users depende sa capability ng mga network devices and resources na meron. Just take note na a small office is a small independent office na nangangailangan lang ng network interconnection between end users to access yung mga shared resources like printers and the internet. Hindi na nya kailangan ng extra connection like VPN or a WAN connection to another remote office.
Yung network environment or site naman kung saan halos lahat ng mga information resources at
servers ng isang organization ay located.
Ang isang main office ay pwedeng magkaroon ng hundreds or more end-users na connected sa
network for their day-to-day jobs.
Since ang main office ay isang typical large network environment, yung mga connected
networks nito can span multiple floors or multiple buildings.
A branch office is actually a small office na gumagamit ng networking to access shared hardware
and network resources. In some instances may mga servers na located on-premise depending on the number of end-users.
Take note na ang difference ng isang branch office dun sa small office in a SOHO network
is - yung small office sa SOHO is an independent network, meaning yung network connection ng small office is only used for sharing resources within the network and also to connect to the internet.
Branch Offices on the other hand is also a small office but, it is not independent - dahil interconnected sya via WAN (Wide Area Network) connections like leased line, MPLS, VPN
to access shared resources from the main office.
Ang usual scenario nyan is 1 main office, and multiple smaller branch offices that uses networking
to connect to the main office to access shared resources from servers located dun sa main office ng isang organization.
When dealing with networks, palagi mong mae-encounter yung LAN and WAN terminology.
Ano ba ang ibig sabihin nyan?
LAN stands for Local Area Network. Yan ay isang collection ng mga network devices that are interconnected sa isang physical location lang - pwedeng sa home network, SOHO network, pwedeng sa isang building, or LAN networks within multiple buildings na magkakatabi.
Yung number of users connected to a LAN can be as small as one user, or thousands of users.
What is important to note pag pinaguusapan yung LAN is - yung location ng network.
LAN connects network devices sa isang pirasong limited area lang.
Yung multiple buildings scenario is also called a Campus Network.
A Campus Network is an interconnection of Local Area Networks (LANs) implemented within multiple buildings located inside a limited geographical area not more than 5km.
So, isipin mo na lang dito sa Campus Network yung Googleplex which is a collection of buildings owned by Google na located dun sa main HQ nila. Bawat isang building ay may implemented na LAN, at bawat isang building na yun ay interconnected sa isa't isa for sharing of resources. Since yung Googleplex ay isang malaking space with multiple buildings interconnected - ang tawag dun sa network nila is a campus network.
A campus network is just a larger type of LAN implementation.
Ano ang difference ng LAN sa WAN?
WAN stands for Wide Area Network. Yan naman ay interconnection of local area networks that covers a larger geographical location. Yung interconnection ng LANs na yan must use a WAN connection such as leased lines, MPLS, and frame-relay.
The internet is actually a WAN, and the world's largest WAN for that matter - dahil interconnection yan ng different organizational networks hosting different servers that shares information, data, applications, etc. for all users connected.
Dito sa WAN, imagine meron tayong main office located at Makati, and meron tayong multiple branch offices - yung isa nasa Cebu, yung isa nasa Davao. Yung dalawang branch offices na yan needs to connect to the Makati main office kung saan located yung mga servers kung saan naka-store yung mga organizational data nila.
Since nasa magkakalayong lugar nakalagay yung mga branch offices and their main office - they need to have a WAN connection (either leased line, frame-relay, or MPLS) to connect.
And yung interconnection between the branch offices and the main office is called a Wide Area Network (WAN).
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