48 lines
1.7 KiB
Markdown
48 lines
1.7 KiB
Markdown
---
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title: Internet_fundamentals
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tags: [networks]
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created: Saturday, August 03, 2024
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---
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# Internet fundamentals
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The internet is a _[network](Network_fundamentals.md) of networks_. A globally
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connected set of computer networks that all use a suite of common
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[protocols](Network_protocols.md).
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The protocols governing the communication between networks on the internet are
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specified in the **Internet Protocol Suite**.
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This combines two protocols:
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- **TCP**
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- The Transmission Control Protocol
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- **IP**
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- The Internet Protocol
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Hence the Internet Protocol Suite is also known as "TCP/IP".
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The TCP/IP is a network stack comprising four layers, each with its own
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protocols. From the top:
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- The **Link Layer** concerns communication between devices on the same local
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network. The transfer of information once it has been received from the
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internet or its transfer between devices before it sent out into the internet.
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Ethernet and WiFi are two core protocols utilised at this layer.
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- The **Internet Layer** is concerned with communication accross networks. It is
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responsible for identifying hosts on the inter-network by their addresses and
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routing data from network to network.
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- The **Transport Layer** come back to this
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- The **Application Layer** is concerned with software that utilises information
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received and sent over the internet, for instance web pages and emails. This
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is the highest level of abstraction for which all the lower levels serve as
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"plumbing". Examples of protocols operative at the Application Layer include
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HTTP and SSH.
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The Link Layer ... The Internet Layer ... The Transport Layer ... The
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Application Layer ...
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