Using Mac Addresses To Exempt Traffic From Authentication And Authorization - Cisco PIX 500 Series Configuration Manual

Using MAC Addresses to Exempt Traffic from Authentication and Authorization

Using MAC Addresses to Exempt Traffic from Authentication
and Authorization
The security appliance can exempt from authentication and authorization any traffic from specific MAC
addresses. For example, if the security appliance authenticates TCP traffic originating on a particular
network but you want to allow unauthenticated TCP connections from a specific server, you would use
a MAC exempt rule to exempt from authentication and authorization any traffic from the server specified
by the rule.
This feature is particularly useful to exempt devices such as IP phones that cannot respond to
authentication prompts.
To use MAC addresses to exempt traffic from authentication and authorization, perform the following
steps:
To configure a MAC list, enter the following command:
Step 1
hostname(config)# mac-list id {deny | permit} mac macmask
Where the id argument is the hexadecimal number that you assign to the MAC list. To group a set of
MAC addresses, enter the mac-list command as many times as needed with the same ID value. Because
you can only use one MAC list for AAA exemption, be sure that your MAC list includes all the MAC
addresses you want to exempt. You can create multiple MAC lists, but you can only use one at a time.
The order of entries matters, because the packet uses the first entry it matches, as opposed to a best match
scenario. If you have a permit entry, and you want to deny an address that is allowed by the permit entry,
be sure to enter the deny entry before the permit entry.
The mac argument specifies the source MAC address in 12-digit hexadecimal form; that is,
nnnn.nnnn.nnnn.
The macmask argument specifies the portion of the MAC address that should be used for matching. For
example, ffff.ffff.ffff matches the MAC address exactly. ffff.ffff.0000 matches only the first 8 digits.
To exempt traffic for the MAC addresses specified in a particular MAC list, enter the following
Step 2
command:
hostname(config)# aaa mac-exempt match id
Where id is the string identifying the MAC list containing the MAC addresses whose traffic is to be
exempt from authentication and authorization. You can only enter one instance of the aaa mac-exempt
command.
The following example bypasses authentication for a single MAC address:
hostname(config)# mac-list abc permit 00a0.c95d.0282 ffff.ffff.ffff
hostname(config)# aaa mac-exempt match abc
The following entry bypasses authentication for all Cisco IP Phones, which have the hardware ID
0003.E3:
hostname(config)# mac-list acd permit 0003.E300.0000 FFFF.FF00.0000
hostname(config)# aaa mac-exempt match acd
The following example bypasses authentication for a a group of MAC addresses except for
00a0.c95d.02b2. Enter the deny statement before the permit statement, because 00a0.c95d.02b2 matches
the permit statement as well, and if it is first, the deny statement will never be matched.
Cisco Security Appliance Command Line Configuration Guide
19-16
Chapter 19 Applying AAA for Network Access
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