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4️⃣ IP addresses V4

The fourth version of the Internet Protocol (IP)

IP v4 addresses use the format

Four sets of three digits ranging between 0-255 separated by a full stop. The number 0 and 255 are not usually used for IP addresses. Each set of digits is called an octet

Typically, addresses appear as: - IP Address - Subnet Mask

Part of the IP address relates to a network address and part to a node address. (Submet mask)

IP Address Classes#

The first octet of an IP address specifies which class an address belongs to

For each class of addresses a default subnet mask exists.

IP Address (first octet)ClassDefault subnet mask

Special IP addresses#

IP AddressDetail Class A - Class B - Class C
169.254..Issued due to APIPA test

Automatic Private IP Addressing
A feature available in Windows that caters for DHCP issues. If there are problems with the DHCP server and an IP Address cannot be obtained dynamically then a special class B address in the range of 169.254.*.* will be issued that given limited network functionality.

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