McAfee EPOCDE-AA-BA Product Guide - Page 273

Data gathering and communications to the server, Systems that host sensors

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Detecting Rogue Systems How the Rogue System Sensor works 21 The sensor further filters on systems that were already detected: • The sensor reports any system the first time it is detected on the network. • For each detected system, the sensor adds the MAC address to the packet filter, so that it is not detected again, until the user-configured time elapses. • The sensor implements aging on the MAC filter. After a specified time, MAC addresses for systems that have already been detected are removed from the filter, causing those systems to be re-detected and reported to the server. This process ensures that you receive accurate and current information about detected systems. Data gathering and communications to the server Once the sensor detects a system on the local network, it gathers information about that system by actively scanning using NetBIOS calls and OS fingerprinting. The gathered information includes: • DNS name • Operating system version • NetBIOS information (domain membership, system name, and the list of currently logged-on users) All NetBIOS-related information that is gathered is subject to standard limitations of authorization, and other limitations documented in the Microsoft management API. The sensor packages the gathered information into an XML message, then sends the message via secure HTTPS to the ePolicy Orchestrator server for processing. The server then uses the ePolicy Orchestrator data to determine whether the system is a rogue system. Bandwidth use and sensor configuration To save bandwidth in large deployments, you can configure how often the sensor sends detection messages to the server. You can configure the sensor to cache detection events for a given time period, such as one hour, then to send a single message containing all the events from that time period. For more information, see Configuring Rogue System Detection policy settings. Systems that host sensors Install sensors on systems that are likely to remain on and connected to the network at all times, such as servers. If you don't have a server running in a given broadcast segment, install sensors on several workstations to ensure that at least one sensor is connected to the network at all times. To guarantee that your Rogue System Detection coverage is complete, you must install at least one sensor in each broadcast segment of your network. Installing more than one sensor in a broadcast segment does not create issues around duplicate messages because the server filters any duplicates. However, additional active sensors in each subnet results in traffic sent from each sensor to the server. While maintaining as many as five or ten sensors in a broadcast segment should not cause any bandwidth issues, you should not maintain more sensors in a broadcast segment than is necessary to guarantee coverage. McAfee® ePolicy Orchestrator® 4.6.0 Software Product Guide 273

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The sensor further filters on systems that were already detected:
The sensor reports any system the first time it is detected on the network.
For each detected system, the sensor adds the MAC address to the packet filter, so that it is not
detected again, until the user-configured time elapses.
The sensor implements aging on the MAC filter. After a specified time, MAC addresses for systems
that have already been detected are removed from the filter, causing those systems to be
re-detected and reported to the server. This process ensures that you receive accurate and current
information about detected systems.
Data gathering and communications to the server
Once the sensor detects a system on the local network, it gathers information about that system by
actively scanning using NetBIOS calls and OS fingerprinting.
The gathered information includes:
DNS name
Operating system version
NetBIOS information (domain membership, system name, and the list of currently logged-on users)
All NetBIOS-related information that is gathered is subject to standard limitations of authorization,
and other limitations documented in the Microsoft management API.
The sensor packages the gathered information into an XML message, then sends the message via
secure HTTPS to the ePolicy Orchestrator server for processing. The server then uses the ePolicy
Orchestrator data to determine whether the system is a rogue system.
Bandwidth use and sensor configuration
To save bandwidth in large deployments, you can configure how often the sensor sends detection
messages to the server. You can configure the sensor to cache detection events for a given time
period, such as one hour, then to send a single message containing all the events from that time
period. For more information, see
Configuring Rogue System Detection policy settings
.
Systems that host sensors
Install sensors on systems that are likely to remain on and connected to the network at all times, such
as servers. If you don’t have a server running in a given broadcast segment, install sensors on several
workstations to ensure that at least one sensor is connected to the network at all times.
To guarantee that your Rogue System Detection coverage is complete,
you must install at least one sensor in each broadcast segment of your
network. Installing more than one sensor in a broadcast segment does
not create issues around duplicate messages because the server filters
any duplicates. However, additional active sensors in each subnet results
in traffic sent from each sensor to the server. While maintaining as many
as five or ten sensors in a broadcast segment should not cause any
bandwidth issues, you should not maintain more sensors in a broadcast
segment than is necessary to guarantee coverage.
Detecting Rogue Systems
How the Rogue System Sensor works
21
McAfee
®
ePolicy Orchestrator
®
4.6.0 Software Product Guide
273