Encapsulating
Other identifiers, such as MAC-48 and EUI-48 values, can be contained within a larger identifier or 'container', such as EUI-64, by creating the larger identifier through a process of combining the smaller identifier with specified values placed in specified bit-positions within the larger identifier – this process is known as 'encapsulation' and is provided for the purpose of easing the transition from MAC-48 and EUI-48 to EUI-64 and to provide a mechanism for the conversion of MAC-48 and EUI-48 identifiers to EUI-64 in such a way that duplicate or conflicting values are avoided.
Encapsulation of MAC-48 within EUI-64 Example:
Assuming that an organization has registered the OUI of AC-DE-48 and that the organization has created the MAC-48 value of AC-DE-48-23-45-67 by concatenating the extension identifier 23-45-67, this MAC-48 identifier has the following binary transmission order:
| OUI | extension identifier | field | 1st | 2nd | 3rd | 4th | 5th | 6th | octet | C A | E D | 8 4 | 3 2 | 5 4 | 7 6 | hex 0011 0101 0111 1011 0001 0010 1100 0100 1010 0010 1110 0110 bits | | | | | | | | | | | | lsb msb lsb msb lsb msb lsb msb lsb msb lsb msbThe same MAC-48 identifier after encapsulation within an EUI-64 has the following transmission order:
| OUI | MAC label | extension identifier | field | 1st | 2nd | 3rd | 4th | 5th | 6th | 7th | 8th | order | C A | E D | 8 4 | F F | F F | 3 2 | 5 4 | 7 6 | hex 00110101 01111011 00010010 11111111 11111111 11000100 10100100 11100110 bits | | | | | | | | | | | | | | | | lsb msb lsb msb lsb msb lsb msb lsb msb lsb msb lsb msb lsb msbThe same MAC-48 identifier after encapsulation within an EUI-64 has the following significance order:
| OUI | MAC label | extension identifier | field | AC | DE | 48 | FF | FF | 23 | 45 | 67 | hex 10101100 11011110 01001000 11111111 11111111 00100011 01000101 01100111 bits | | | | | most-significant-byte least-significant-byte | most-significant-bit least-significant-bitEncapsulation of EUI-48 within EUI-64 Example:
Assuming that an organization has registered the OUI of AC-DE-48 and that the organization has created the EUI-48 value of AC-DE-48-23-45-67 by concatenating the extension identifier 23-45-67, this EUI-48 identifier has the following format in significance order:
| company_id | extension identifier | field | AC | DE | 48 | 23 | 45 | 67 | hex 10101100 11011110 01001000 00100011 01000101 01100111 bits | | | | | most-significant-byte least-significant-byte | most-significant-bit least-significant-bitThe same EUI-48 identifier after encapsulation within an EUI-64 has the following format in significance order:
| company_id | EUI label | extension identifier | field | AC | DE | 48 | FF | FE | 23 | 45 | 67 | hex 10101100 11011110 01001000 11111111 11111110 00100011 01000101 01100111 bits | | | | | most-significant-byte least-significant-byte | most-significant-bit least-significant-bitEncapsulation of MAC-48 or EUI-48 within Modified EUI-64 Example:
In the encapsulation within a Modified EUI-64 a MAC-48 is treated as an EUI-48 and the U/L bit is inverted. Assuming that an organization has registered the OUI of AC-DE-48 and that the organization has created the MAC-48 or EUI-48 value of AC-DE-48-23-45-67 by concatenating the extension identifier 23-45-67, this MAC-48 or EUI-48 identifier has the following format in significance order:
| company_id | extension identifier | field | AC | DE | 48 | 23 | 45 | 67 | hex 10101100 11011110 01001000 00100011 01000101 01100111 bits | | | | | most-significant-byte least-significant-byte | most-significant-bit least-significant-bitThe same MAC-48 or EUI-48 identifier after encapsulation within a Modified EUI-64 has the following format in significance order:
| company_id | EUI label | extension identifier | field | AE | DE | 48 | FF | FE | 23 | 45 | 67 | hex 10101110 11011110 01001000 11111111 11111110 00100011 01000101 01100111 bits | | | | | most-significant-byte least-significant-byte | most-significant-bit least-significant-bitRead more about this topic: Organizationally Unique Identifier