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Possibly the most important aspect to computers: the internet (or more broadly, the network). Here are some guidelines to setting up networks on Linux machines with special sections for the virtual machine controlled by [https://www.virtualbox.org/ VirtualBox].
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==Getting Started==<p>
This first item of note is the location of the file that names the network connections in Linux. This file can be found [[This Is Your Brain On Informatics: Common Pathnames|here]] under the network section. Upon being opened the file should show something similar to this (# indicates a comment):
The networks shown here are the basic networks that will allow the machine to connect to the internet. If this is a regular computer (not a virtual machine), this file should be similar to what is above meaning that it is already completely setup for internet connection and ssh purposes.
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<p>Also, notice Notice here that the eth0 network has "dhcp" (dynamic host configuration protocol) at the end of the final line. This causes the IP address of this network to be dynamically acquired (meaning that the IP address will be changed frequently) rather than statically set. Below is a discussion of how to set up each. </p>
==Adding a network== <p>
This step should be taken care of if it is a regular computer; however it is very necessary for a virtual machine.
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===Using a Dynamically Acquired IP===<p>This method will cause the network to randomly (within reason of course) select an IP address each time the virtual box is disconnected from an ISP (Internet Service Provider) or another virtual machine is created.<br /><br />
'''Vitual Machine Note'''<br />
This step is critical to allowing the virtual machine to interact with the outside world and not have a host only network. The steps below are for a virtual box, but can be applied to any other network setup in Linux.
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# Access the above pathname with pico (pico /etc/network/interfaces)
## Type "ifconfig" into the command line and check the IP next to the "inet addr:"
</p><br /><br /> ===Using a Static IP===<p>
This can be used if it is necessary to prevent the IP address from changing (e.g. a home server or you're just sick of having to adjust the IP for every program that connects to the virtual machine each time it changes). Below is an example of how it is set.
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The key component of this is the word ''static'' at the end of the line beginning with ''iface'', forcing the IP address to bet set statically as determined by the user. Each of the components of the network must now be set individually. The address is the network address and can be set to anything. Typically only the last number is changed from what is currently set The current IP address can be determined by using the Linux command [[This Is Your Brain On Informatics: Linux Commands|''ifconfig'']] and looking at the ''inet addr'' under the appropriate network. ''Bcast'' will determine the broadcast and ''Mask'' will determine the netmask. As long as only the final number of the IP address is changed, then these can be used as is.
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<p>The key component of this is the word ''static'' at the end of the line beginning with ''iface'', forcing the IP address to bet set statically as determined by the user. Each of the components of the network must now be set individually. The address is the network address and can be set to anything. Typically only the last number is changed from what is currently set. The current IP address can be determined by using the Linux command [[This Is Your Brain On Informatics: Linux Commands|''ifconfig'']] and looking at the ''inet addr'' under the appropriate network. ''Bcast'' will determine the ''broadcast'' and ''netmask'' will determine the Mask. As long as only the final number of the IP address is changed, then these can be used as shown above. The final numbers (''network'' and ''broadcast'') can be set by simply using 0 and 1 255 respectively for the last number. Finally, the ''gateway'' is the IP address of the router used to access the internet. This can be accessed from the router settings. The ''gateway'' should NOT be set for a '''Virtual Machine''' through VirtualBox. It should only be set for an actual computer. The gateway is typically the same first three numbers as the IP address with a ''1'' as the last number.</p>
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