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Cisco Intrusion Prevention System Sensor CLI Configuration Guide for IPS 7.2
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Appendix A System Architecture
MainApp
Understanding the ARC
The main responsibility of the ARC is to block events. When it responds to a block, it either interacts
with the devices it is managing directly to enable the block or it sends a block request through the Control
Transaction Server to a master blocking sensor. The web server on the master blocking sensor receives
the control transaction and passes it to the Control Transaction Server, which passes it to the ARC. The
ARC on the master blocking sensor then interacts with the devices it is managing to enable the block.
Figure A-4 illustrates the ARC.
Figure A-4 ARC
Note
An ARC instance can control 0, 1, or many network devices. The ARC d oes not share control of any
network device with other ARC applications, IPS management software, other network ma nagement
software, or system administrators. Only one ARC instance is allowed to run on a given sensor.
The ARC initiates a block in response to one of the following:
An alert event generated from a signature that is configured with a block action
A block configured manually through the CLI, IDM, IME, o r ASDM
A block configured permanently against a host or network address
When you configure the ARC to block a device, it initiates either a Telnet or SSH connection with the
device. The ARC maintains the connection with each device. After the block is initiated, the ARC pushes
a new set of configurations or ACLs (one for each interface direction) to each controlled device. When
a block is completed, all configurations or ACLs are updated to remove the block.
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Sensor
Block
Subscription
Block Event Event Store
Block CT
Block CT
Response
Block
Subscription
Block Event
Block CT
Block CT
Response
CT Source
Master Blocking Sensor
Block CT
Block CT
Response
Block CT
Block CT
Response
CT Server
Web Server
Block CT Block CT
Response
IDAPI
Attack
Response
Controller
IDAPI
Attack
Response
Controller
Routers and Firewalls
Routers and Firewalls