In Routers and Switches we learned several things such as: what is a Router, why we need Routers, what is the importance of a Router. We also learned what VLSM is and how to do it and use it. Throughout CCNA we learned how to configure a Router; the different types of Routing protocols and most importantly what, when and how to use those protocols in the field. Finally I will discuss Switches in how they are use to set up a LAN. Throughout this paper these topic will be discuss to cover what was learned through class lecture and text book (CCNA study guide by Lammle) and actually applied through hands on labs which were done with actual Cisco Router and Switches within a working LAN and Ethernet connection environment.
What is a Router? According to tech-faq.com “a router is a network device with interfaces in multiple networks whose task is to copy packets from one network to another”. CCNA Study Guide defines it as “a network layer mechanism, either software or hardware, using one or more metric to decide on the best path to use for transmission of network traffic. Sending packets between networks by routers is based on the information provide on network layers. Historically, the device has sometimes been called a gateway.” The best way to understand what a router is would be to understand its purpose which is to direct or send information packet from one network to another whether it be LAN or WAN. We must also understand that though it has other function this is more of what a router does and interns makes a router what it is. Let’s look at the Importance of a router.
How important is a router. Well let’s start off by asking this question, what would happen if there was no routers? How would we connect outside of our network range not to mention within in our LAN that is broken in to small network if we did not have them? Without routers we could only communicate with nodes within our range if we are a class A then within that range we can communicate, since there is no router that hold information pertaining to any class B address A cannot talk to them it does not know how to reach them. So without routers we cannot communicate to other classes just our Class A network (our private network) thus leaving the network no communication with other networks. There is also a problem there as well, what about subnetting when you need to break down your class A range this would be hard to utilize without a router as well because they would be seen as another network and there is the routing problem again. This is why routers are very important in any network and these are just soon of the problems of a network without a router.
What is VLSM? First VLSM stand for Variable Length Subnet Mask. It is used to take an IP range of a given class and break it down to smaller network giving it different subnets for certain network ranges even though they are in the same class. Doing this gives us more use of the IP range without wasting or having a lot of unused IP addresses. A common example if I had a class B full range but need to connect small network all together with router and switches I couldn’t they would have to be all in one network. Now if I use VLSM I could take and assign different ranges to network and nodes, whether the network is in another area or there is a printer that needs to be access from all networks locally. With VLSM we can do these things and more, it is also used for a Local Area Network (LAN) that is connected by switches and a single router. There is a lot of things made possible with VLSM in a network infrastructure. Finally the definition of VLSM helps optimize available address space and specify a different subnet mask for the same number on various subnets (Lammle, 2007). Let’s briefly identify how to configure a router. To enter the router to prepare to configure you need a terminal and a console and telnet if it on a connected network. Let’s say we are on a...