The DS8000 supports the use of Internet Protocol Version 4 (IPv4) and Internet Protocol Version 6 (IPv6). Customer network ports can be configured using the hardware management console (HMC) to use either or both standards. IPv6 provides a higher level of security than IPv4.
An IPv4 address is 32 bits. An IP Address is shown as 4 decimal numbers representing 4 bytes: d.d.d.d where d = decimal number (0 - 255). High order bits are the network identifier and lower order bits are the host identifier. The number of bits in a network identifier is defined by a subnet mask which looks like an IP address with all 1s in high order bits and all 0s in low order bits (for example, 255.255.255.0). An IP address with the host identifier set to all 1s is a broadcast address for all hosts on the network. An IP address can also include a port number. The port number follows the IP address and is separated by a colon (for example, 250.250.250.1:8451).
An IPv6 address is 128 bits. The preferred IP address format has 8 hexadecimal numbers representing 16 bytes (for example, x:x:x:x:x:x:x:x (x = X‘0' - X‘FFFF')). An IPv6 address can contain an embedded IPv4 address. The format has 6 hexadecimal and 4 decimal numbers representing 16 bytes (for example, x:x:x:x:x:x:d.d.d.d (x = ‘0'x - X‘FFFF' and d = 0 - 255)). A compressed form allows one string of 0s to be replaced by ‘::' (for example, FF01:0:0:0:0:0:0:1A2 can be represented by FF01::1A2). High order bits are for the subnet prefix. Lower order bits are for the interface identifier.
An IPv6 address can have a number of bits in a subnet prefix that are defined by a decimal prefix following the IP address (for example, FF01::101/96 has a 96–bit subnet prefix and a 32–bit interface identifier). Most IPv6 address are required to have a 64–bit prefix length. Specific high order bit combinations in the subnet prefix are defined for specific purposes. An IPv6 IP address can also specify an IP port number (for example, [x:x:x:x:x:x:x:x]:p, where p = decimal number).