** Cisco Certified Networking Associate (CCNA) is an entry point for a future networking professional. It gives us an overview of the networking world and provides us with a solid foundational knowledge in the area.CCNA consists of two exams: ICND1 and ICND2. Upon successful completion of ICND1 you become a Cisco Certified Entry-level Networking Technician (CCENT). CCENT combined with ICND2 is a CCNA certificate.I've read several books on CCNA and liked none of them, primarily because of their length. I've designed my lessons to be short and no-nonsense, yet but informative and helpful at the same time. I hope readers will find these lessons useful on their way to the CCNA certification. ** This is the first lesson in the series and it is about networks in general, what they consist of, and some cabling types you should learn and remember.A network
is a means for communication, or getting something from point A to point B. Traditional networks consist of roads, railways, seaways, etc. A modern network, or a computer network, consists of routers, switches, servers, clients, wireless access points, cable lines, etc. The Internet is just a huge interconnected collection of these things. Components of a network:
- A switch
is a device that interconnects computers in a Local Area Network (LAN). LAN is a network within a limited area, such as your house, school or office. - A router,
on the other hand, interconnects devices in a Wide Area Network (WAN), which could be between two cities, or even countries.
- A Wireless Access Point
is what provides you with WiFi connections. I like to call it a Wireless Switch, though, because it more accurately describes its functions.
- A client
is a device which is in hand of an end user, for example in yours. Your smartphone is a client, your PC is a client, and your Google Glass is a client. - A server
is a computer which provides you with some service, may it be a website access or file storage.Note:
A wireless router (probably the router you have at your house) is a router with integrated Wireless Access Point. Wireless APs themselves don’t provide you with routing functions (i.e. don’t interconnect devices in WAN). Cable types:
or Shielded Twisted Pair
– consists of 4 pairs of twisted wires. Wires are twisted to cancel out electromagnetic interference (EMI) and a metallic foil, which wraps each pair, provides extra EMI cancellation- UTP
or Unshielded Twisted Pair
– same thing as STP, but with no metallic foil.STP and UTP are both standard cables for Ethernet. Maximum possible length of a twisted pair cable is 100 meters. Signal loses its strength and has to be regenerated to pass that distance.A plug that's used with twisted pair cables is called an RJ-45 connector, a slot in which the connector is inserted – Rj-45 jack.
- Fiber optic cable
– uses glass or plastic as a medium. Can carry data over long distances.
- Serial cable
– old cabling type for serial communication. Still used to connect to console ports of Cisco devices. (more on that in later)
Thanks and stay tuned for parts 2 and 3.