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User Guide for Cisco Secure Access Control System 5.4
OL-26225-01
Chapter4 Common Scenarios Usin g ACS
Agentless Network Access
ACS supports host lookup for the following identity stores:
•Internal hosts
•External LDAP
•Internal users
•Active Directory
You can access the Active Directory via the LDAP API.
You can use the Internal Users identity store for Host Lookup in cases where the relevant host is already
listed in the Internal Users identity store, and you prefer not to move the data to the Internal Hosts
identity store.
ACS uses the MAC format (XX-XX-XX-XX-XX-XX) and no other conversions are possible. To search
the Internal Users identity store using the User-Name attribute (for example, xx:xx:xx:xx:xx:xx) you
should leave the Process Host Lookup option unchecked. ACS will handle the request as a PAP request.
When MAC address authentication over PAP or EAP-MD5 is not detected according to the Host Lookup
configuration, authentication and authorization occur like regular user authentic ation over PAP or
EAP-MD5. You can use any identity store that supports these authentication protocols. ACS uses the
MAC address format as presented in the RADIUS User-Name attribute.
Related Topics
•Creating an Access Service for Host Lookup, page 4-18
•Viewing and Performing Bulk Operations for Internal Identity Store Hosts, page 8-18
•Managing Users and Identity Stores, page8-1
•Authentication with Call Check, page4-14
Authentication with Call Check
When ACS identifies a network access request with the call check attribute as Host Lookup
(RADIUS::ServiceType = 10), ACS authenticates (validates) and authorizes the host by looking up the
value in the Calling-Station-ID attribute (for example, the MAC address) in the configured identity store
according to the authentication policy.
When ACS receives a RADIUS message, it performs basic parsing and validation, and then checks if the
Call Check attribute, RADIUS ServiceType(6), is equal to the value 10. If the RADIUS ServiceType is
equal to 10, ACS sets the system dictionary attribute UseCase to a value of Host Lookup.
In the ACS packet processing flow, the detection of Host Lookup according to Call Check service-type
is done before the service selection policy. It is possible to use the condition UseCase equals Host
Lookup in the service selection policy.
Initially, when RADIUS requests are processed, the RADIUS User-Name attribute is copied to the
System UserName attribute. When the RADIUS Service-Type equals 10, the RADIUS
Calling-Station-ID attribute is copied to the System User-Name attribute, and it overrides the RADIUS
User-Name attribute value.
ACS supports four MAC address formats:
•Six groups of two hexadecimal digits, separated by hyphens—01-23-45-67-89-AB
•Six groups of two hexadecimal digits, separated by colons—01:23:45:67:89:AB
•Three groups of four hexadecimal digits, separated by dots—0123.4567.89AB