Configuring IDS Blocking Using VMS IDS MC
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Contents
Introduction
This document provides a sample for the configuration of the Cisco Intrusion Detection System (IDS) via the VPN/Security Management Solution (VMS), IDS Management Console (IDS MC). In this case, Blocking from the IDS Sensor to a Cisco router is configured.
Prerequisites
Requirements
Before you configure Blocking, ensure you have met these conditions.
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The Sensor is installed and configured for sensing necessary traffic.
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The sniffing interface is spanned to the router outside interface.
Components Used
The information in this document is based on these software and hardware versions.
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VMS 2.2 with IDS MC and Security Monitor 1.2.3
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Cisco IDS Sensor 4.1.3S(63)
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Cisco Router running Cisco IOS® Software Release 12.3.5
The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, make sure that you understand the potential impact of any command.
Conventions
For more information on document conventions, see the Cisco Technical Tips Conventions.
Configure
In this section, you are presented with the information to configure the features described in this document.
Note: To find additional information on the commands used in this document, use the Command Lookup Tool (registered customers only) .
Network Diagram
This document uses the network setup shown in this diagram.
Configurations
This document uses the configurations shown here.
| Router Light |
|---|
Current configuration : 906 bytes ! version 12.3 service timestamps debug uptime service timestamps log uptime no service password-encryption ! hostname light ! enable password cisco ! username cisco password 0 cisco ip subnet-zero ! ! ! ip ssh time-out 120 ip ssh authentication-retries 3 ! call rsvp-sync ! ! ! fax interface-type modem mta receive maximum-recipients 0 ! controller E1 2/0 ! ! ! interface FastEthernet0/0 ip address 100.100.100.2 255.255.255.0 duplex auto speed auto ! interface FastEthernet0/1 ip address 1.1.1.1 255.255.255.0 duplex auto speed auto ! interface BRI4/0 no ip address shutdown ! interface BRI4/1 no ip address shutdown ! interface BRI4/2 no ip address shutdown ! interface BRI4/3 no ip address shutdown ! ip classless ip route 0.0.0.0 0.0.0.0 100.100.100.1 ip http server ip pim bidir-enable ! ! dial-peer cor custom ! ! line con 0 line 97 108 line aux 0 line vty 0 4 login ! end |
| Router House |
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Building configuration... Current configuration : 797 bytes ! version 12.3 no service pad service timestamps debug datetime msec service timestamps log datetime msec no service password-encryption ! hostname House ! logging queue-limit 100 enable password cisco ! ip subnet-zero no ip domain lookup ! ! interface Ethernet0 ip address 10.66.79.210 255.255.255.224 hold-queue 100 out ! interface Ethernet1 ip address 100.100.100.1 255.255.255.0 !--- After Blocking is configured, the IDS Sensor !--- adds this access-group ip access-group. IDS_Ethernet1_in_0 in ip classless ip route 0.0.0.0 0.0.0.0 10.66.79.193 ip route 1.1.1.0 255.255.255.0 100.100.100.2 ip http server no ip http secure-server ! !--- After Blocking is configured, the IDS Sensor !--- adds this access list. ip access-list extended IDS_Ethernet1_in_0. permit ip host 10.66.79.195 any permit ip any any ! line con 0 stopbits 1 line vty 0 4 password cisco login ! scheduler max-task-time 5000 end |
Initial Sensor Configuration
Complete these steps to initially configure the Sensor.
Note: If you have performed the initial setup of your Sensor, proceed to the section Importing the Sensor into IDS MC.
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Console into the Sensor.
You are prompted for a username and password. If this is the first time you are consoling into the Sensor, you must login with the username cisco and password cisco.
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You are prompted to change the password and then re-type the new password to confirm.
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Type setup and enter the appropriate information at each prompt to set up basic parameters for your Sensor, as per this example:
sensor5#setup --- System Configuration Dialog --- At any point you may enter a question mark '?' for help. User ctrl-c to abort configuration dialog at any prompt. Default settings are in square brackets '[]'. Current Configuration: networkParams ipAddress 10.66.79.195 netmask 255.255.255.224 defaultGateway 10.66.79.193 hostname sensor5 telnetOption enabled accessList ipAddress 10.66.79.0 netmask 255.255.255.0 exit timeParams summerTimeParams active-selection none exit exit service webServer general ports 443 exit exit -
Press 2 in order to save your configuration.
Import the Sensor into IDS MC
Complete these steps to import the Sensor into the IDS MC.
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Browse to your Sensor.
In this case, browse to either http://10.66.79.250:1741 or https://10.66.79.250:1742.
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Login with the appropriate username and password.
In this example, the username admin and password cisco were used.
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Select VPN/Security Management Solution > Management Center and choose IDS Sensors.
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Click the Devices tab, select Sensor Group, highlight Global, and click Create Subgroup.
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Enter the Group Name and ensure the Default radio button is selected, then click OK to add the subgroup into the IDS MC.
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Select Devices > Sensor, highlight the subgroup created in the previous step (in this case, test), and click Add.
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Highlight the subgroup, and click Next.
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Enter the details as per this example, then click Next to continue.
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After you are presented with a message that states Successfully imported sensor configuration, click Finish to continue.
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Your Sensor is imported into the IDS MC. In this case, sensor5 is imported.
Import the Sensor into Security Monitor
Complete this procedure to import the Sensor into the security monitor.
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At the VMS Server menu, select VPN/Security Management Solution > Monitoring Center > Security Monitor.
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Select the Devices tab, then click Import and enter the IDS MC Server Information, as per this example.
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Select your Sensor (in this case, sensor5) and click Next to continue.
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If need be, update the Network Address Translation (NAT) address for your Sensor, then click Finish to continue.
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Click OK to finish importing the Sensor from IDS MC into Security Monitor.
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Your Sensor is successfully imported.
Use IDS MC for Signature Updates
Complete this procedure to use the IDS MC for signature updates.
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Download the Network IDS Signature updates (registered customers only) from the Downloads and save them in the C:\PROGRA~1\CSCOpx\MDC\etc\ids\updates\ directory on your VMS server.
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At the VMS server console, select VPN/Security Management Solution > Management Center > Sensors.
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Click the Configuration tab, select Updates, and click Update Network IDS Signatures.
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Select the signature you want to upgrade from the drop-down menu and click Apply to continue.
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Select the Sensor(s) to update, and click Next to continue.
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After you are prompted to apply the update to the Management Center, as well as the Sensor, click Finish to continue.
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Telnet or console into the Sensor command line interface. Information similar to this appears:
sensor5# Broadcast message from root (Mon Dec 15 11:42:05 2003): Applying update IDS-sig-4.1-3-S63. This may take several minutes. Please do not reboot the sensor during this update. Broadcast message from root (Mon Dec 15 11:42:34 2003): Update complete. sensorApp is restarting This may take several minutes.
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Wait for a few minutes to allow the upgrade to complete, then enter show version to verify.
sensor5#show version Application Partition: Cisco Systems Intrusion Detection Sensor, Version 4.1(3)S63 Upgrade History: * IDS-sig-4.1-3-S62 07:03:04 UTC Thu Dec 04 2003 IDS-sig-4.1-3-S63.rpm.pkg 11:42:01 UTC Mon Dec 15 2003
Configure Blocking for the IOS Router
Complete this procedure to configure Blocking for the IOS router.
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At the VMS server console, select VPN/Security Management Solution > Management Center > IDS Sensors.
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Select the Configuration tab, select your Sensor from Object Selector, and click Settings.
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Select Signatures, click Custom, then click Add to add a new signature.
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Enter the new Signature Name, then select the Engine (in this case, STRING.TCP).
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You can customize the available parameters by checking the appropriate radio button and clicking Edit.
In this example, the ServicePorts parameter is edited to change its value to 23 (for port 23). The RegexString parameter is also edited to add the value testattack. When this is complete, click OK to continue.
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To edit the Signature Severity and Actions or to Enable/Disable the signature, click the name of the signature.
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In this case, the severity is changed to High and the Block Host action is selected. Click OK to continue.
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The Block Host blocks attacking IP hosts or IP subnets.
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The Block Connection blocks TCP or UDP ports (based on attacking TCP or UDP connections).
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The complete signature looks similar to this:
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In order to configure the Blocking Device, select Blocking > Blocking Devices from the Object Selector (the menu on the left hand side of the screen), and click Add to enter the following information:
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Click Edit Interfaces (see previous screen capture), click Add, enter this information, then click OK to continue.
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Click OK twice to complete the configuration of the Blocking device.
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To configure Blocking Properties, select Blocking > Blocking Properties.
The Length of Automatic Block can be modified. In this case, it is changed to 15 minutes. Click Apply to continue.
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Select Configuration from the main menu, then select Pending, check the pending configuration to ensure it is correct, and click Save.
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To push the configuration changes to the Sensor, generate and then deploy the changes by selecting Deployment > Generate and click Apply.
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Select Deployment > Deploy, then click Submit.
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Check the checkbox next to your Sensor, then click Deploy.
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Check the checkbox for the job in the queue, then click Next to continue.
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Enter the Job Name and schedule the job as Immediate, then click Finish.
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Select Deployment > Deploy > Pending.
Wait a few minutes until all the pending jobs have been completed. The queue is then empty.
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To confirm the deployment, select Configuration> History.
Ensure the status of the configuration is displayed as Deployed. This means that the Sensor configuration has been updated successfully.
Verify
This section provides information you can use to confirm your configuration is working properly.
Certain show commands are supported by the Output Interpreter Tool (registered customers only) , which allows you to view an analysis of show command output.
Launch the Attack and Blocking
To verify that the Blocking process is working correctly, launch a test attack and check the results.
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Before launching the attack, select VPN/Security Management Solution > Monitoring Center > Security Monitor.
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Choose Monitor from the main menu, click Events and then click Launch Event Viewer.
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Telnet to the router (in this case, Telnet to the House router), to verify the communication from the Sensor.
house#show user Line User Host(s) Idle Location * 0 con 0 idle 00:00:00 226 vty 0 idle 00:00:17 10.66.79.195 house#show access-list Extended IP access list IDS_Ethernet1_in_0 10 permit ip host 10.66.79.195 any 20 permit ip any any (20 matches) House# -
To launch the attack, Telnet from one router to the other and type testattack.
In this case, we used Telnet to connect from the Light router to the House router. As soon as you press <space> or <enter>, after typing testattack, your Telnet session should be reset.
light#telnet 100.100.100.1 Trying 100.100.100.1 ... Open User Access Verification Password: house>en Password: house#testattack !--- Host 100.100.100.2 has been blocked due to the !--- signature "testattack" being triggered. [Connection to 100.100.100.1 lost]
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Telnet to the router (House) and enter the command show access-list.
house#show access-list Extended IP access list IDS_Ethernet1_in_1 10 permit ip host 10.66.79.195 any !--- You will see a temporary entry has been added to !--- the access list to block the router from which you connected via Telnet previously. 20 deny ip host 100.100.100.2 any (37 matches) 30 permit ip any any
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From the Event Viewer, click Query Database for new events now to view the alert for the previously launched attack.
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In the Event Viewer, highlight and right-click the alarm, then select View Context Buffer or View NSDB to view more detailed information about the alarm.
Note: The NSDB is also available online at the Cisco Secure Encyclopedia (registered customers only) .
Troubleshoot
Troubleshooting Procedure
Use the following procedure for troubleshooting purposes.
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In the IDS MC, select Reports > Generate.
Depending on the problem type, further detail should be found in one of the seven available reports.
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At the Sensor console, enter the command show statistics networkaccess and check the output to ensure the "state" is active.
sensor5#show statistics networkAccess Current Configuration AllowSensorShun = false ShunMaxEntries = 100 NetDevice Type = Cisco IP = 10.66.79.210 NATAddr = 0.0.0.0 Communications = telnet ShunInterface InterfaceName = FastEthernet0/1 InterfaceDirection = in State ShunEnable = true NetDevice IP = 10.66.79.210 AclSupport = uses Named ACLs State = Active ShunnedAddr Host IP = 100.100.100.2 ShunMinutes = 15 MinutesRemaining = 12 sensor5# -
Ensure the communication parameter shows that the correct protocol is being used, such as Telnet or Secure Shell (SSH) with 3DES.
You can try a manual SSH or Telnet from an SSH/Telnet client on a PC to check username and password credentials are correct. You can then try Telnet or SSH from the Sensor itself, to the router, to ensure you are able to login successfully.
Related Information
Revision History
| Revision | Publish Date | Comments |
|---|---|---|
1.0 |
16-Jun-2008 |
Initial Release |
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