CS-MARS Integration for Cisco Unified Wireless
A secure unified network, featuring both wired and wireless access, requires an integrated, defense-in-depth approach to security, including cross-network anomaly detection and correlation that is critical to effective threat detection and mitigation.
This chapter outlines how CS-MARS can be integrated with a Cisco Unified Wireless Network to extend cross-network anomaly detection and correlation to the WLAN, providing network security staff with visibility across all elements of the network.
Software implementation, screenshots, and behavior referenced in this chapter are based on the releases listed in Test Bed Hardware and Software. It is assumed that the reader is already familiar with both CS-MARS and the Cisco Unified Wireless Network.
Note This guide addresses only CS-MARS features specific to Cisco Unified Wireless integration.
CS-MARS Cross-Network Security Monitoring
CS-MARS security monitoring combines cross-network intelligence, sophisticated event correlation, and threat validation to effectively identify potential network and application threats.
Network intelligence is gained through the efficient aggregation and correlation of massive amounts of network and security data from devices across the network, including network devices and host applications from Cisco and other vendors. This extensive monitoring enables critical visibility into overall network status, traffic flows, and events. For more information on CS-MARS, refer to Reference Documents.
Figure 9-1 CS-MARS Cross-Network Anomaly Detection and Correlation
Extending CS-MARS Visibility to Cisco Unified Wireless
CS-MARS Release 5.3.2 introduced native support for Cisco Unified Wireless Network devices that extends visibility to the WLAN, integrating WLAN events into its threat detection, investigation, mitigation, and reporting capabilities.
This includes visibility into WLAN events such as:
•WLAN DoS attacks
•Ad hoc networks
•Client exclusions and blacklisting
•WLAN operational status
For more information, refer to CS-MARS for Cisco Unified Wireless Features.
CS-MARS is complementary to the WLAN-specific anomaly detection and correlation features offered by the Cisco WLC and Wireless Control System (WCS), offering network security staff an integrated view of the entire network that is critical to cross-network anomaly detection and correlation.
For more information on WCS, refer to Reference Documents.
Implementing CS-MARS and Cisco WLC Integration
Configuring the Cisco WLC
In order for CS-MARS to obtain visibility into events on a Cisco Unified Wireless Network, each Cisco WLC must be configured to send SNMP traps to CS-MARS.
In addition, if CS-MARS discovery of each WLC and its connected LWAPP APs is required, a read-only community string must also be configured on each WLC. This enables CS-MARS to query the WLC and obtain this information.
The configuration steps required to enable CS-MARS and WLC integration are:
1. Enable SNMP v1 (CS-MARS currently only supports SNMP v1).
2. Define the community settings for use with CS-MARS.
3. Verify that the required SNMP traps are enabled.
4. Define CS-MARS as an SNMP trap receiver.
The following are detailed instructions on how to implement each of these steps:
Step 1 Enable SNMP v1.
On the WLC, go to Management -> SNMP -> General. Verify the general SNMP parameters, set the state box next to SNMP v1 Mode to Enable and click Apply (see Figure 9-2).
Figure 9-2 Enabling SNMP v1 on a Cisco WLC
Note SNMP v1 is disabled by default on the WLC.
Step 2 Define the community settings for use with CS-MARS.
On the WLC, go to Management -> SNMP -> Communities. Define a read-only community string for use with CS-MARS and the source IP address and mask of the CS-MARS management station. Set the access mode to Read Only, the status to Enable, and then click Apply (see Figure 9-3).
Figure 9-3 Defining the Community Settings for Use with CS-MARS
Note the following:
•If the IP address and IP Mask fields are left blank, they default to 0.0.0.0/0.0.0.0, permitting read-only access with this community string to any source IP address.
•It is recommended that access with any particular community string is restricted to only authorized source IP addresses.
•SNMP v1 passes all data in clear text, including the community strings, and is thus vulnerable to sniffing. Customers should review their security policy to determine if additional security techniques, such as IPSec or an out-of-band (OOB) management network, are required to protect SNMP v1 transactions.
•CS-MARS should only be granted read-only access. This is all that is required and ensures that only minimum necessary access privileges are granted, as recommended as a security best practice.
Step 3 Verify that the required SNMP traps are enabled.
On the WLC, go to Management -> SNMP -> Trap Controls. SNMP traps are sent for all events that have their associated checkbox checked. Set the trap controls required for monitoring and click Apply (see Figure 9-4).
Figure 9-4 Verifying WLC SNMP Trap Controls
Step 4 Define CS-MARS as an SNMP trap receiver.
On the WLC, go to Management -> SNMP -> Trap Receivers. Add a new SNMP trap receiver with the name and IP address of CS-MARS. Set the status to Enable and click Apply (see Figure 9-5).
Figure 9-5 Defining CS-MARS as an SNMP Trap Receiver
In order for CS-MARS to discover each Cisco WLC and its connected LWAPP APs, each WLC must be defined on CS-MARS. This provides CS-MARS with SNMP read-only access to the device so that it can obtain this and other device-specific information. This is the only configuration required on CS-MARS.
Manually Adding a Cisco WLC
To manually add a Cisco WLC to CS-MARS, complete the following steps:
Step 1 On the CS-MARS GUI, navigate to ADMIN -> System Setup. In the middle section titled Device Configuration and Discovery Information, select Security and Monitor Devices (see Figure 9-6).
Figure 9-6 CS-MARS System Setup Screen
Step 2 On the Security and Monitoring Information screen, as shown in Figure 9-7, click Add.
Figure 9-7 CS-MARS Screen to Add a New Device
Step 3 Add a Cisco WLC from the device type drop-down box by scrolling down to and selecting Cisco WLAN Controller 4.x.
Note WLCs running Cisco Unified Wireless Network Software Release 5.x are supported and can be configured as a Cisco WLAN Controller 4.x (see Figure 9-8).
Figure 9-8 Adding a Cisco WLC on CS-MARS
The device entry fields change to reflect this device type and the WLC can be defined by entering this information:
•Device Name—WLC name
•Access IP—WLC IP address to be used for SNMP read-only access
•Reporting IP—WLC management interface IP address used as the source IP address for SNMP traps
•Access Type—Select SNMP (the only option available in the drop-down box)
•SNMP RO Community—SNMP community name defined on the WLC for use with CS-MARS
•Interface Information—WLC management interface IP address and network mask
Step 4 Once all the WLC information has been defined, click Discover (see Figure 9-9).
Figure 9-9 Defining a Cisco WLC on CS-MARS
Note the following:
•The WLC management interface must be defined. Other interfaces will automatically be added upon successful discovery of the device.
•SNMP v1 access must already be enabled on the WLC for discovery to be successful (see Configuring the Cisco WLC).
Upon successful discovery of the WLC, any other interfaces and any currently associated access points are discovered and populated on the CS-MARS interface (see Figure 9-10).
If discovery is not successful, verify that:
•CS-MARS can ping the WLC.
•SNMP v1 is enabled on the WLC.
•SNMP community string defined on CS-MARS matches that defined on the WLC for CS-MARS.
•SNMP community string for CS-MARS is enabled on the WLC.
•CS-MARS source IP address matches that defined on the WLC.
Figure 9-10 Successful Cisco WLC Discovery on CS-MARS
Step 5 Select Submit and then Activate the configuration.
Note that CS-MARS identifies an access point (AP) based on its MAC address rather than the typical Access IP/Reporting IP. To view the MAC address of a particular AP, scroll to the bottom of the WLC device page, check the box next to the name of an AP and click Edit Access Point (see Figure 9-12).
Figure 9-11 Viewing a Cisco LWAPP Access Point on CS-MARS
The AP device name and MAC address is subsequently displayed (see Figure 9-12).
Figure 9-12 Cisco LWAPP Access Point as a Device on CS-MARS
Note The MAC address of access points must be unique to enable accurate event logging.
For more information on how CS-MARS parses events from Cisco LWAPP APs, refer to CS-MARS WLAN AP Event Parsing.
CS-MARS for Cisco Unified Wireless Features
This section provides a brief overview of the CS-MARS features to support Cisco Unified Wireless.
More information on the CS-MARS wireless LAN features is available in the CS-MARS User Guide (see Reference Documents).
CS-MARS support for Cisco Unified Wireless devices includes visibility into WLAN events such as:
•WLAN DoS attacks
•Ad hoc networks
•WLAN operational status
To view all the WLAN events parsed by CS-MARS:
Step 1 Navigate to MANAGEMENT -> Event Management.
Step 2 Select Cisco WLAN Controller 4.x from the pull down menu to review all the WLC events (see Figure 9-13).
Figure 9-13 Sample Subset of CS-MARS WLAN Events
This screen presents all the events related to Cisco WLAN controllers that CS-MARS natively supports.
Event Groups Featuring WLAN Events
CS-MARS correlates WLAN events into WLAN-specific and general event groups, as outlined in Table 9-1.
Table 9-1 Event Groups
Info/High Usage/Network Device
In CS-MARS queries and reports, the Event Group is represented as "Event Type".
Rules Based on WLAN Events
CS-MARS features the WLAN-specific inspection rules shown in Table 9-2.
Table 9-2 Rules Based on WLAN Events
System Rule: Operational Issue: WLAN
System: Operational Issue
System Rule: Rogue WLAN AP Detected
System: Operational Issue
System Rule: WLAN DoS Attack Detected
System: Network Attacks and DoS
These rules are enabled by default and integrated into existing rule groups.
To view the details of a CS-MARS rule:
Step 1 Navigate to RULES.
Step 2 Scroll down the list to find the rule.
If you know which Rule Group a rule belongs to, you can filter the list by selecting the appropriate Rule Group in the drop-down box next to Group (see Figure 9-14).
Figure 9-14 Viewing CS-MARS Rules by Rule Group\
The details of a particular rule can be viewed by selecting that rule and then clicking Edit.
As an example, the default details of the rule System Rule: Rogue WLAN AP Detected are shown in Figure 9-15.
Figure 9-15 CS-MARS Rule Rogue WLAN AP Detected
Queries and Reports Featuring WLAN Events
CS-MARS features WLAN-specific queries and reports, including:
•WLAN DoS Attacks Detected
•WLAN Probes Detected
•WLAN Rogue AP or Adhoc Hosts Detected
•WLAN Successful Mitigations
WLAN events are also integrated into existing queries and reports, as appropriate, for example:
•Network Attacks and DoS
Running a Query on WLAN Events
To run a query on particular WLAN-specific events:
Step 1 Navigate to QUERY/REPORTS.
Step 2 From the drop-down box Select Report..., select the desired WLAN-specific report.
If you know which Report Group a report belongs to, you can filter the list by selecting the appropriate Report Group in the drop-down box Select Group... (see Figure 9-16).
Figure 9-16 CS-MARS WLAN-Specific Reports
Ensure the query timeframe is as required (shown here for the last one hour interval) and click Submit Inline (see Figure 9-17).
Figure 9-17 Sample CS-MARS Rogue WLAN AP Report
Generating a Report on WLAN Events
Events that have been correlated into event sets can be expanded to view the individual events and their associated raw message.
To generate a report on particular WLAN-specific events:
Step 1 Navigate to QUERY/REPORTS -> Report.
Step 2 From the drop-down box Group --Report Groups -, select, the desired Report Group (see Figure 9-18).
Figure 9-18 Selecting a CS-MARS Report by Report Group
The reports available within that Report Group are then displayed (see Figure 9-19).
Figure 9-19 CS-MARS Network Attacks and DoS Report Group
Step 3 Select the report of interest and, unless the report was recently generated, click Resubmit.
To view the newly generated report, click View Report (see Figure 9-20).
Figure 9-20 Generating and Viewing a CS-MARS Report
The report is then displayed (see Figure 9-21).
Figure 9-21 Sample CS-MARS WLAN Rogue AP Report
General Guidelines for CS-MARS Integration for Cisco Unified Wireless
General guidelines for extending CS-MARS monitoring to the Cisco Unified Wireless Network include the following:
•Enable CS-MARS monitoring of the Cisco Unified Wireless Network to provide cross-network visibility
•Ensure access point MAC addresses are unique
•Consider developing custom rules that use the rich set of WLAN events to further extend CS-MARS capabilities
•Use WCS for detailed analysis and investigation of WLAN events
CS-MARS for Cisco Unified Wireless Operational Considerations
This section outlines some operational considerations when extending CS-MARS cross-network anomaly detection and correlation to the Cisco Unified Wireless Network.
•The reporting device for Cisco Unified Wireless events is the name of the WLC or AP that generated the event.
•The WLC and AP often only identify and report WLAN anomalies based on the MAC address of the device generating the anomaly. Related information, such as source and destination IP address, port, or protocol are typically not reported. If this is the case, CS-MARS displays the WLAN event with a source and destination IP address of 0.0.0.0, a source and destination port of 0, and a protocol of N/A. The MAC address of the device identified as the source of the anomaly is available in the raw message.
•CS-MARS does not currently perform event classification or correlation based on the MAC address of the device generating a WLAN anomaly. For detailed WLAN-specific event anomaly detection and correlation, the Cisco WLC and Wireless Control System (WCS) can be leveraged to enable further investigation of anomalies identified by CS-MARS.
•CS-MARS false positive tuning is performed based on source or destination IP address. Since many WLAN anomalies, such as rogue AP reporting, do not have a client source or destination IP address, this is not currently possible. However, extensive rogue device classification capabilities were introduced in Cisco Unified Wireless Release 5.0 and these should be leveraged to aid incident investigation. For more details on this feature, refer to Reference Documents.
•A custom parser can be used to extend CS-MARS native parsing of WLAN events, for example, to use the WLAN anomaly source MAC address. For more details on this CS-MARS capability, refer to Reference Documents.
•CS-MARS currently only supports SNMP v1, which passes all data in clear text, including the community strings, and is thus vulnerable to sniffing. It is recommended that customers review their security policy to determine if additional security techniques, such as IPSec or an out-of-band (OOB) management network, are required to protect SNMP v1 transactions. General best practices include the use of strong, non-trivial community strings, removing default community strings, restricting access to authorized originators only, and granting only read-only access. For more information on securing SNMP access, refer to the Network Security Baseline document in General Network Security.
CS-MARS WLAN AP Event Parsing
In order for CS-MARS to discover and parse events from Cisco LWAPP access points, the Cisco WLC must first be defined as a reporting device in CS-MARS. The steps required to define a Cisco WLC as a reporting device in CS-MARS are outlined in detail earlier in this chapter.
The WLC receives events from the APs that it monitors and then forwards these events as SNMP traps. The source IP address of the trap is always the WLC. However, if an AP generated the original event, the MAC address of the AP is embedded in the SNMP trap as an OID (object identifier).
CS-MARS parses these SNMP traps in order to accurately identify the reporting device.
When CS-MARS receives an SNMP trap from a WLC that includes the MAC address of an AP as the event originator, the manner in which the event is parsed depends upon whether CS-MARS has an AP with a matching MAC address already defined or not:
•If the AP MAC address is known, CS-MARS presents the AP device name as the reporting device
•If the AP MAC address is unknown, CS-MARS presents this first event with the WLC device name as the reporting device and also, automatically, defines the AP as a child agent of the WLC sending the trap. Subsequent events are thus accurately attributed to the AP as the reporting device, since it is defined as a device and identifiable based on its MAC address.
This progressive, automatic discovery of new, undefined, or previously undiscovered APs eliminates the need for manual definition.
Note Progressive auto-discovery of the access points requires SNMPv1 read access to be enabled on the WLC. For information on configuring the WLC, refer to Configuring the Cisco WLC.
If an AP MAC address is unknown and automatic discovery fails, the event is attributed to the WLC.
WLC SNMP traps that do not include AP MAC address information are attributed to the WLC as the reporting device.
CS-MARS Integration for Cisco Unified Wireless Dependencies
CS-MARS and Cisco WLC integration is dependent upon the software and hardware platforms shown in Table 9-3.
Table 9-3 CS-MARS and Cisco WLC Integration Dependencies
Release 5.3.2 or later
Release 6.0 supports both Gen1 and Gen2 hardware
Release 5.3.2 supports Gen2 hardware (110 and 210) only
Cisco Unified Wireless Release 4.x or later
LWAPP APs only
Test Bed Hardware and Software
Integration testing was performed and verified using the CS-MARS and WLC platforms and software releases shown in Table 9-4.
Table 9-4 Test Bed Hardware and Software
Wireless Services Module (WiSM) in Cisco Catalyst 6500 Series
Cisco Unified Wireless
•Cisco Wireless Control System (WCS)
•Managing Rogue Devices
Cisco Wireless LAN Controller Configuration Guide, Release 5.0 http://www.cisco.com/en/US/docs/wireless/controller/5.0/configuration/guide/c5sol.html#wp1345692
•Configuring Wireless LAN Devices
User Guide for Cisco Security MARS Local Controller, Release 5.3.x http://www.cisco.com/en/US/docs/security/security_management/cs-mars/5.3/user/guide/local_controller/cfgwlan.html
•Configuring Custom Devices
User Guide for Cisco Security MARS Local Controller, Release 5.3.x http://www.cisco.com/en/US/docs/security/security_management/cs-mars/5.3/user/guide/local_controller/cfgcustm.html
User Guide for Cisco Security MARS Local and Global Controllers, Release 6.x http://www.cisco.com/en/US/docs/security/security_management/cs-mars/6.0/user/guide/combo/cfgCustm.html
General Network Security
•Network Security Baseline