Switch configuration is done the same way as router configuration, but has different goals as switches are different devices than routers. One of the most common uses for configuring a switch is to set up and modify VLANS to segregate access... but port security is also a common thing, making sure people can't just plug into one of your switches to get access.
There's a video showing the process here.
Monday, November 21, 2011
Routing Protocols
A protocol in this instance is a set of rules for passing around data. There's a few well-known and widely-used routing protocols (such as RIP/V2 and EIGRP), and they often fall into classifications such as internal and external depending on their intended use. This page has some information about the different classifications.
Technical Support
"Is it plugged in?"
"Is the monitor turned on?"
"Are you sure that's a router and not a microwave?"
If these questions seem familiar to you then you've likely dealt with tech support often. While the basic questions may seem aggravating, often they're important and overlooked. That said, once you run past the basic troubleshooting steps with your ISP or other service provider, you're often handed off to a technician that knows how the network was set up, perhaps even the person who helped install it. While it may seem annoying, it's important to let them test what they need to in order to find where the problem lies.
"Is the monitor turned on?"
"Are you sure that's a router and not a microwave?"
If these questions seem familiar to you then you've likely dealt with tech support often. While the basic questions may seem aggravating, often they're important and overlooked. That said, once you run past the basic troubleshooting steps with your ISP or other service provider, you're often handed off to a technician that knows how the network was set up, perhaps even the person who helped install it. While it may seem annoying, it's important to let them test what they need to in order to find where the problem lies.
Router Configuration
Router configuration is generally done through a command-line interface. In most cases initial configuration is done by connecting the AUX port on the router to the serial port on a computer and running a terminal emulation program (such as PuTTY).
Once in standard protocol involves setting up permissions via locking admin access with an encrypted password, then allowing/denying certain ports access and setting up a routing protocol, then assigning IP addresses to interfaces so that the router and allow communication through itself, but only as you deem fit.
Once in standard protocol involves setting up permissions via locking admin access with an encrypted password, then allowing/denying certain ports access and setting up a routing protocol, then assigning IP addresses to interfaces so that the router and allow communication through itself, but only as you deem fit.
Subnetting
Subnetting is the process of dividing a single IPv4 network into multiple smaller networks (subnets) in order to segregate them. This can be done to apply various policies to only nodes in a certain subnet, or simply for segregating groups of nodes from another to block off communication.
Subnetting does have downsides, however. There needs to be a network ID and broadcast ID for each subnet, so for each subnet you lose two usable IPs. If you have enough subnets then you may be limited to a small number of usable hosts per subnet (down to the single digits). The amount of networks and hosts per network depends on the number of bits "borrowed" (noted with the slash notation).
Subnetting does have downsides, however. There needs to be a network ID and broadcast ID for each subnet, so for each subnet you lose two usable IPs. If you have enough subnets then you may be limited to a small number of usable hosts per subnet (down to the single digits). The amount of networks and hosts per network depends on the number of bits "borrowed" (noted with the slash notation).
ISP
ISP is the Internet Service Provider you get your internet service from. Depending on whether you're a home consumer or a business consumer the deals you make will be different, but it generally revolves around buying a specific package for a specific type of internet speed/bandwidth (upload and download), and support that comes with it. Depending on your area, there will be certain ISPs available.
Network Media
There's multiple types of network media, and the type you use will depend on your needs. One major division is wired versus wireless. Wireless has pros (such as not having to run wires everywhere) and cons (such as more sources of interference, and signals being broadcast), and in many cases wired is the choice for reliability and security.
Even within those categories there's many choices. For wireless there's WiFi, Bluetooth, IR, and microwave/satellite, within wired there's STP/UTP, coax, fiber, and more. Each kind has varying costs and bandwidth possibilities, so it's important to know what your goals are before picking out network media.
Even within those categories there's many choices. For wireless there's WiFi, Bluetooth, IR, and microwave/satellite, within wired there's STP/UTP, coax, fiber, and more. Each kind has varying costs and bandwidth possibilities, so it's important to know what your goals are before picking out network media.
Troubleshooting
It's said that a large number of network connectivity problems are due to the media, but still many people skip checking the cables and jump straight into software troubleshooting, spending perhaps hours of wasted effort before the actual problem is found.
There's multiple approaches to troubleshooting (top-down, bottom-up, divide-and-conquer), the correct one to take will often depend on the situation. Often the best way too approach something is not to try to decide which layer is likely to contain the issue, but to first rule out other layers by checking them individually, so that you're left troubleshooting only the layers that have a possibility of containing the issue.
There's multiple approaches to troubleshooting (top-down, bottom-up, divide-and-conquer), the correct one to take will often depend on the situation. Often the best way too approach something is not to try to decide which layer is likely to contain the issue, but to first rule out other layers by checking them individually, so that you're left troubleshooting only the layers that have a possibility of containing the issue.
OSI Reference Model
The OSI Reference Model is a method of defining and displaying the various interconnections that happen within a network. The layers go up in complexity near the top of the list, and devices and protocols on the same layer will communicate with each other.
For example if you have two switches on a network, then even though they'll be passing all sorts of information back and forth that encompasses all the layers, but the switches themselves will only be concerned with and interpret information on layer-2. While layer-1 information is passed to them, their Network Interface cards will handle that, and while information for higher layers is sent as well, it's contained within the information that the switches are passing around.
For example if you have two switches on a network, then even though they'll be passing all sorts of information back and forth that encompasses all the layers, but the switches themselves will only be concerned with and interpret information on layer-2. While layer-1 information is passed to them, their Network Interface cards will handle that, and while information for higher layers is sent as well, it's contained within the information that the switches are passing around.
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