public static SubnetInfo[] SplitIPv4Subnet(IPAddress ipv4Address, IPAddress subnetmask, IPAddress newSubnetmask, CancellationToken cancellationToken)
{
ConcurrentBag <SubnetInfo> bag = new ConcurrentBag <SubnetInfo>();
// Calculate the current subnet
SubnetInfo subnetInfo = CalculateIPv4Subnet(ipv4Address, subnetmask);
int newCidr = Subnetmask.ConvertSubnetmaskToCidr(newSubnetmask);
// Get new HostBits based on SubnetBits (CIDR) // Hostbits (32 - /24 = 8 -> 00000000000000000000000011111111)
string newHostBits = (new string('1', (32 - newCidr))).PadLeft(32, '0');
// Convert Bits to Int64, add +1 to get all available IPs
int newTotalIPs = Convert.ToInt32(newHostBits, 2) + 1;
// Get bytes...
byte[] networkAddressBytes = subnetInfo.NetworkAddress.GetAddressBytes();
// Get int...
if (BitConverter.IsLittleEndian)
{
Array.Reverse(networkAddressBytes);
}
int networkAddress = BitConverter.ToInt32(networkAddressBytes, 0);
Parallel.For(0, subnetInfo.IPAddresses / newTotalIPs, new ParallelOptions()
{
CancellationToken = cancellationToken
}, i =>
{
byte[] newNetworkAddressBytes = BitConverter.GetBytes(networkAddress + (int)(newTotalIPs * i));
if (BitConverter.IsLittleEndian)
{
Array.Reverse(newNetworkAddressBytes);
}
SubnetInfo info = CalculateIPv4Subnet(new IPAddress(newNetworkAddressBytes), newSubnetmask);
bag.Add(new SubnetInfo(info.NetworkAddress, info.Broadcast, info.IPAddresses, info.Subnetmask, info.CIDR, info.HostFirstIP, info.HostLastIP, info.Hosts));
});
return(bag.ToArray());
}
public static SubnetInfo CalculateIPv4Subnet(IPAddress ipv4Address, IPAddress subnetmask)
{
IPAddress networkAddress = GetIPv4NetworkAddress(ipv4Address, subnetmask);
IPAddress broadcast = GetIPv4Broadcast(ipv4Address, subnetmask);
int cidr = Subnetmask.ConvertSubnetmaskToCidr(subnetmask);
long totalIPs = Subnetmask.GetNumberIPv4Addresses(cidr);
// Fix bug when /31 (host first/last can be null)
IPAddress hostFirstIP = null;
IPAddress hostLastIP = null;
long hostIPs = 0;
if (totalIPs == 1) // Fix bug when /32 (show range for 1 IP)
{
hostFirstIP = networkAddress;
hostLastIP = broadcast;
hostIPs = 0;
}
else if (totalIPs > 2) // Calculate for /0-/30
{
hostFirstIP = IPv4AddressHelper.IncrementIPv4Address(networkAddress, 1);
hostLastIP = IPv4AddressHelper.DecrementIPv4Address(broadcast, 1);
hostIPs = totalIPs - 2;
}
return(new SubnetInfo
{
NetworkAddress = networkAddress,
Broadcast = broadcast,
IPAddresses = totalIPs,
Subnetmask = subnetmask,
CIDR = cidr,
HostFirstIP = hostFirstIP,
HostLastIP = hostLastIP,
Hosts = hostIPs
});
}
