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Probably the most well known network layer protocol is, of course, IP or Internet protocol.

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As I mentioned in the beginning of the course.

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The Internet protocol or IP is responsible for addressing hosts.

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Encapsulating data into packets or datagrams, including fragmentation and reassembly.

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And routing packets from a source host to a destination host across one or more IP networks.

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So like other layer three protocols, IP is connectionless, which means it doesn't care whether the

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packet has reached the destination or not.

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That's what Layer four is for.

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All right.

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So there are two versions of IP that currently coexist within the global Internet IP version four or

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IPV four and IP version six or IPV six.

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IP addresses are made up of binary values and drive the routing of all data over the internet.

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IPV four addresses are 32 bits long and IPV six addresses are 128 bits long.

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Right now.

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We're going to see each of the versions in detail.

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But before we move on, let's compare the main features of each version.

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IPV four is a 32 bit address and IPV six is a 128 bit address.

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Now theoretically you can address two to the power of 32 devices in IPV four, which is about 4.3 billion.

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Right.

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In IPV six.

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On the other hand, you can address two to the power of 128 devices, which is, well, um, well,

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let's see.

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Why don't you just do the math on your own?

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So IPV four is represented by the decimal equivalent of four octets separated by dots.

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The biggest number one can make with eight binary digits is two to the power of eight minus one, which

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means 255.

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So each octet can be any number from 0 to 2.

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Five five.

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Right.

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Now 128 bit IPV six addresses are written using hexadecimal as opposed to dotted decimal in IPV four.

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So because a hexadecimal number uses four bits, this means that an IPV six address consists of 32 hexadecimal

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numbers.

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These numbers are grouped in fours, giving eight groups or blocks.

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The groups are written with a colon as a separator.