FireBrick FB6602, Руководство пользователя

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Appendix C. MAC Addresses usage
Ethernet networks use 48 bit MAC addresses. These are globally unique and allocated by the equipment
manufacturer from a pool of addresses that is defined by the first three octets (bytes), which identify the
organization, and are known as the Organizationally Unique Identifier (OUI). OUIs are issued by the IEEE -
more information, and a searchable database of existing OUIs are available at http://standards.ieee.org/develop/
regauth/oui/
MAC addresses are commonly written as six groups of two hexadecimal digits, separated by colons or hyphens.
FB6000s currently ship with an OUI value of 00:03:97.
In principle the FireBrick could have a single MAC address for all operations. However, practical experience
has led to the use of multiple MAC addresses on the FireBrick. A unique block of addresses is assigned to each
FireBrick, with the size of the block dependent on the model.
Most of the time, FB6000 users do not need to know what MAC addresses the product uses. However, there
are occasions where this information is useful, such as when trying to identify what IP address a DHCP server
has allocated to a specific FB6000. For information on how MAC addresses are used by the FB6000, please
refer to this article on the FireBrick website [http://www.firebrick.co.uk/fb2700/mac.php]
The label attached to the bottom of the FB6000 shows what MAC address range that unit uses, using a compact
notation, as highlighted in Figure C.1 :-
Figure C.1. Product label showing MAC address range
In this example, the range is specified as :-
000397:147C-F
this is interpreted as :-
• All addresses in the range start with 00:03:97:14:7
• the next digit then ranges from "C" through to "F"
• the first address in the range has zero for the remaining digits (
C:00
)
• the last address in the range has F for the remaining digits ( F:FF )
Therefore this range spans
00:03:97:14:7C:00
to
00:03:97:14:7F:FF
inclusive (1024 addresses).
If you trying to identify an IP address allocation, note that the exact address used within this range depends
on a number of factors ; generally you should look for an IP address allocation against any of the addresses
in the range.
Alternatively, if the range specification doesn't include a hyphen, it specifies that all addresses in the range start
with this 'prefix' - the first address in the range will have zero for all the remaining digits, and the last address
in the range will have F for all the remaining digits. For example :-