Technical data

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Ipv4 and Ipv6
IPv6 is version 6 of the Internet-protocol, the new version was drawn up at the end of
the 1990s to replace the current, IPv4 (version 4), mainly because the IP addresses are
starting to come to an end. The greatest difference between IPv6 and IPv4 is that the
address length has been increased from 32 bits to 128 bits. This means the number of
possible addresses has been increased from 4 billion to a real astronomical number.
Ipv6 header
Subnetwork division
Local networks with more than a few hundred connected devices are unusual; allow-
ing this kind of network to take up its own A or B Class (Over 16 million networks
with 65000 devices possible on each network) is an immense waste of available
addresses. Most of these classes are therefore divided into a subnetwork, where a
part of the device identity is used as a type of network address. The division is made
by utilising a part of the device identity, i.e. the “border” between the network address
and the device identity is “moved” so that the number of available network identities is
increased, at the same time as the number of devices in the subnetwork decreases. In
order to achieve this a netmask is used where the bits that belong to the network
part are set to one (and the computer bits are set to zero).
Smaller networks are easier to administrate, the data traffic in the subnetwork is less,
the physical network becomes easier to set up and maintain (for example, you can
utilise different subnetworks on different floors of a building), etc.
128 bits source address
Payload length Next header Hop limit
128 bits source address
128 bits destination address
B A C K