Special IP addresses

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Not all IP addresses can be used for hosts. A number of addresses are reserved for special needs.

The first address on the network is a Network address. Network addresses are normally used by routers to form routing tables.

The last address is a "Broadcast address". The packets with the broadcast address should be obtained by all the machines on that network.

Therefore, two IP addresses are always reserved. They are a network address and a broadcast address for that network. A range of IP addresses between those two IPs can be assigned to users.

When creating networks, IPmanager will automatically mark such addresses as special not to allow their assignment to users.

Moreover, IP addresses are considered special not only if they locate on the border of networks, but also on the border of /24 for IPv4, because some operating systems may experience problems when working with those IPs.

You may use them, however you should unassign them after a network is created.

For example, when creating 192.168.0.0/23, you will get the network which size is 512 with 4 IPs marked as in use:

  • 192.168.0.0 - network address
  • 192.168.0.255 - broadcast address for subnet 192.168.0.0/24
  • 192.168.1.0 - address for subnet 192.168.1.0/24
  • 192.168.1.255 - broadcast address