2024-08-06 07:00:03 +01:00
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---
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title: Link_Layer_of_the_Internet_Protocol
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2024-08-06 17:00:03 +01:00
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tags: [networks, internet]
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2024-08-06 07:00:03 +01:00
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created: Tuesday, August 06, 2024
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---
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# Link Layer of the Internet Protocol Suite
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> The Link Layer is the lowest level of the network stack that makes up the
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> Internet Protocol Suite. It is concerned with the physical and logical
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> connections between [hosts](./Network_hosts.md) on the same local network.
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The physical and logical connections are known as **Links**.
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Link Layer protocols goven communication between devices. Examples include:
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- **WiFi**
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- For wireless communication between devices using radio waves
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- **Ethernet**
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- Wired communication
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## MAC addresses
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Each device on a link has a network address that uniquely identifies it. For
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most Link Layer Protocols this is a Media Access Control (MAC) address.
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A device receives data addressed to its MAC address.
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MAC addresses are limited to local networks. Remote networks cannot send data to
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a specific MAC address. This is off-limits from the outside.
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## Frames
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Link Layer data is divided into small units called "frames". The anatomy of a
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frame is as follows:
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```
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--------------------------
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| header | data | footer |
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--------------------------
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```
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The header contains the source and destination MAC address plus a descriptor of
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the type of data it contains. The data is the payload. The footer is used to
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detect errors.
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