AddressAndMaskToIPv4 converts an ipv4 address and a prefix (both uint32 values) into a string in format 'x.y.z.w/q'.

Ipv4CidrToAddressAndMask converts an ipv4 CIDR address in form '1.2.3.4/12' to corresponding uint32 representations of the address and the mask.

Ipv4ToUint32 converts an ipv4 address in form '1.2.3.4' to an uint32 representation of the address.

MaskLength2Mask will tank in an int and return the bit mask for the number given.