24 lines
814 B
Markdown
24 lines
814 B
Markdown
# Internet protocol Version 4 (IPV4)
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- IP is the principal communications protocol in the network layer.
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- IP has the task of delivering packets from source host to destination host based on IP addresses.
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IP defines datagram structure that encapsulate the data to be delivered.
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An IP datagram (packet) consists of a header part an a text part. (payload)
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The header has a 20 byte fixed part an a variable length optional part.
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![[IP-packet.png]]
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Some of the fields in a packet are not always used.
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## Packet encapsulation
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Packets are encapsulated in data link frames (Ethernet)
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![[packet-enscapsulation-2.png]]
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## Fragmentation
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Mostly, data link frames are smaller in size than IP Packets
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In these cases the packet is split up into multiple parts (fragments) and each fragment is send in a separate frame. |