Context-based Access Control

Context-based Access Control(CBAC) filters TCP and UDP packets based on application protocol session information, and actively inspects the activity happening behind the firewall. This provides a more sophisticated way of providing perimeter security. CBAC examines not only the network layer and transport layer but application layer information that is stored in the state table too, this allows them to learn about the state of TCP and UDP sessions. Context-based Access Control(CBAC) filters TCP and UDP packets based on application protocol session information, and actively inspects the activity happening behind the firewall. CBAC watches the outbound traffic determining which packet to be allowed in, making decisions based on how the application behaves instead of only the address and port number the application uses. CBCA also have the ability to open any more inbound channels required for the returning data that were being questioned by the outgoing data for any application.

Benefits of CBAC

- Prevention and detection of CBAC

- Real time alerts and audit trails

CBAC inspection rules allow a per-application protocol basis configuration of alerts and audit trail information, generating real-time alerts and auditing trails. System log is used by audit trails in order to track all network transactions. 

REFERENCE : http://www.cisco.com/en/US/products/sw/secursw/ps1018/products_tech_note09186a0080094e8b.shtml

http://en.wikipedia.org/wiki/Context-based_access_control

http://etutorials.org/Networking/Cisco+Certified+Security+Professional+Certification/Part+II+Securing+the+Network+Perimeter/Chapter+6+IOS+Firewall+Feature+Set+-+CBAC/Context-Based+Access+Control+CBAC/

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