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Table Of Contents
Cisco IOS IPS 5.x Signature Format Support and Usability Enhancements
Prerequisites for Cisco IOS 5.x Format Signatures with Cisco IOS IPS
Restrictions for Cisco IOS 5.x Format Signatures with Cisco IOS IPS
Information About Cisco IOS 5.x Format Signatures with Cisco IOS IPS
Router Configuration Files and Signature Event Action Processor (SEAP)
Benefits of Cisco IOS 5.x Format Signatures with Cisco IOS IPS
Signature Update Accessibility
How to Use Cisco IOS 5.x Format Signatures with Cisco IOS IPS
Retiring All Signatures and Selecting a Category of Signatures
Configuring Cisco IOS IPS on Your Router
Loading a Signature File into Cisco IOS IPS
Flexible Signatures: Ordered and Incremental
Tuning Signatures Per Signature ID
Tuning Signatures Per Category
Setting the Target Value Rating
Enabling Automatic Signature Updates
Automatic Signature Update Guidelines
Monitoring Cisco IOS IPS Signatures via Syslog Messages or SDEE
Cisco IOS IPS Configuration: Example
Feature Information for Cisco IOS 5.x Format Signatures with Cisco IOS IPS
Cisco IOS IPS 5.x Signature Format Support and Usability Enhancements
First Published: November 17, 2006Last Updated: November 17, 2006This feature introduces support for Cisco IOS Intrusion Prevention System (IPS) version 5.0, which is a version-based signature definition XML format. In Cisco IOS Release 12.4(11)T, Cisco IOS IPS 4.x format signatures are replaced by the 5.x format signatures that are used by all other Cisco IPS devices.
Finding Feature Information in This Module
Your Cisco IOS software release may not support all of the features documented in this module. To reach links to specific feature documentation in this module and to see a list of the releases in which each feature is supported, use the "Feature Information for Cisco IOS 5.x Format Signatures with Cisco IOS IPS" section.
Finding Support Information for Platforms and Cisco IOS and Catalyst OS Software Images
Use Cisco Feature Navigator to find information about platform support and Cisco IOS and Catalyst OS software image support. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.
Contents
•
Prerequisites for Cisco IOS 5.x Format Signatures with Cisco IOS IPS
•
Restrictions for Cisco IOS 5.x Format Signatures with Cisco IOS IPS
•
Information About Cisco IOS 5.x Format Signatures with Cisco IOS IPS
•
How to Use Cisco IOS 5.x Format Signatures with Cisco IOS IPS
•
Feature Information for Cisco IOS 5.x Format Signatures with Cisco IOS IPS
Prerequisites for Cisco IOS 5.x Format Signatures with Cisco IOS IPS
System and Image Requirements for Cisco IOS IPS 5.x
•
Cisco IOS IPS signature categories are available in two formats—Basic and Advanced.
•
Cisco IOS IPS system requirements depend on the type of deployment, the bandwidth requirements, and security requirements. The larger the number of signatures, the larger the amount of memory consumed.
•
You must generate a RSA crypto key and load the public signature on your router for signature decryption.
This following cisco public key configuration can be cut and pasted directly into your router configuration:
crypto key pubkey-chain rsanamed-key realm-cisco.pub signaturekey-string 30820122 300D0609 2A864886 F70D0101 01050003 82010F00 3082010A 02820101 00C19E93 A8AF124A D6CC7A24 5097A975 206BE3A2 06FBA13F 6F12CB5B 4E441F16 17E630D5 C02AC252 912BE27F 37FDD9C8 11FC7AF7 DCDD81D9 43CDABC3 6007D128 B199ABCB D34ED0F9 085FADC1 359C189E F30AF10A C0EFB624 7E0764BF 3E53053E 5B2146A9 D7A5EDE3 0298AF03 DED7A5B8 9479039D 20F30663 9AC64B93 C0112A35 FE3F0C87 89BCB7BB 994AE74C FA9E481D F65875D6 85EAF974 6D9CC8E3 F0B08B85 50437722 FFBE85B9 5E4189FF CC189CB9 69C46F9C A84DFBA5 7A0AF99E AD768C36 006CF498 079F88F8 A3B3FB1F 9FB7B3CB 5539E1D1 9693CCBB 551F78D2 892356AE 2F56D826 8918EF3C 80CA4F4D 87BFCA3B BFF668E9 689782A5 CF31CB6E B4B094D3 F3020301 0001 quit
Note
You can also access the public key configuration at the following URL: http://www.cisco.com/cgi-bin/tablebuild.pl/ios-v5sigup
•
You must load one of the following images on your router to install Cisco IOS IPS 5.x: adventerprisek9, advsecurityk9, and advipservicesk9.
Note
To check the current system version, use the show subsys name ips command.
IPS 4.x uses a version format of 2.xxx.xxx; IPS 5.x uses a version format of 3.xxx.xxx.Upgrading from Cisco IOS IPS 4.x to Cisco IOS IPS 5.x Signatures
Cisco IOS IPS 5.x format signatures are not backward compatible with Cisco IOS IPS 4.x. You must reconfigure your Cisco IOS IPS features for use with the IPS 5.x signature format command-line interface (CLI) and features.
When reconfiguring Cisco IOS IPS on a router to convert to the 5.x signature format, you must have the following Cisco IOS IPS 4.x information:
•
Cisco IOS IPS rule name (which was specified via the ip ips name ips-name command)
•
Interfaces for which the Cisco IOS IPS rule has been applied
•
User-created and customized signature definition files (SDFs)
To gather this information, issue the show ip ips configuration command, which displays a copy of the existing output.
Router# show ip ips configuration
Configured SDF Locations:disk2:my-signatures.sdfBuiltin signatures are enabled but not loadedLast successful SDF load time: 05:31:54 MST Sep 20 2003IPS fail closed is disabledFastpath ips is enabledQuick run mode is enabledEvent notification through syslog is enabledEvent notification through SDEE is enabledTotal Active Signatures: 13Total Inactive Signatures: 0Signature 50000:0 disableSignature 50000:1 disableSignature 50000:2 disableIPS Rule ConfigurationIPS name MYIPSInterface ConfigurationInterface GigabitEthernet0/1Inbound IPS rule is MYIPSOutgoing IPS rule is not set
Note
Detailed or customized changes to specific signatures may be lost. IPS 4.x SDF files will not load under the Cisco IOS IPS 5.x version.
Restrictions for Cisco IOS 5.x Format Signatures with Cisco IOS IPS
Warning
Do not enable all IPS signatures. The router may not be able to able to compile all signatures, resulting in high CPU and memory usage, degraded performance, and a system crash.
Backward Compatibility
Cisco IOS IPS 5.x format signatures are not backward compatible with Cisco IOS IPS 4.x SDFs.
Cisco 870 Series Platform Support
The 870 series platform with Cisco IOS IPS in Cisco IOS Release 12.4(11)T may experience lower performance relative to previous releases (CSCsg57228). The Cisco IOS IPS performance on the 870 series platform will be enhanced in a later 12.4(11)T image rebuild.
On the 870 series platform, Cisco IOS IPS is supported only on the adv-ipservices and the adv-enterprise images. Cisco IOS IPS is the same on both images.
Information About Cisco IOS 5.x Format Signatures with Cisco IOS IPS
Before using Cisco IOS 5.x format signatures with Cisco IOS IPS, you should understand the following concepts:
•
Benefits of Cisco IOS 5.x Format Signatures with Cisco IOS IPS
•
Signature Update Accessibility
Cisco IOS IPS Overview
The Cisco IOS IPS acts as an in-line intrusion prevention sensor, watching packets and sessions as they flow through the router and scanning each packet to match any of the Cisco IOS IPS signatures. When it detects suspicious activity, it responds before network security can be compromised and logs the event through Cisco IOS syslog messages or Security Device Event Exchange (SDEE). The network administrator can configure Cisco IOS IPS to choose the appropriate response to various threats. The Signature Event Action Processor (SEAP) can dynamically control actions that are to be taken by a signature event on the basis of parameters such as fidelity, severity, or target value rating. These parameters have default values but can also be configured via CLI. When packets in a session match a signature, Cisco IOS IPS can take any of the following actions, as appropriate:
•
Send an alarm to a syslog server or a centralized management interface
•
Drop the packet
•
Reset the connection
•
Deny traffic from the source IP address of the attacker for a specified amount of time
•
Deny traffic on the connection for which the signature was seen for a specified amount of time
Cisco developed its Cisco IOS software-based intrusion-prevention capabilities and Cisco IOS Firewall with flexibility in mind, so that individual signatures could be disabled in case of false positives. Generally, it is preferable to enable both the firewall and Cisco IOS IPS to support network security policies. However, each of these features may be enabled independently and on different router interfaces.
Signature Categories
Cisco IPS appliances and Cisco IOS IPS with Cisco 5.x format signatures operate with signature categories. All signatures are pregrouped into categories; the categories are hierarchical. An individual signature can belong to more than one category. Top-level categories help to define general types of signatures. Subcategories exist beneath each top-level signature category. (For a list of supported top-level categories, use your router CLI help (?).)
Router Configuration Files and Signature Event Action Processor (SEAP)
As of Cisco IOS Release 12.4(11)T, SDFs are no longer used by Cisco IOS IPS. Instead, routers access signature definition information via a directory that contains three configuration files—the default configuration, the delta configuration, and the SEAP configuration. Cisco IOS accesses this directory via the ip ips config location command.
Note
You must issue the ip ips config location command; otherwise, the configuration files are not saved to any location.
SEAP is the control unit responsible for coordinating the data flow of a signature event. It allows for advanced filtering and signature overrides on the basis of the Event Risk Rating (ERR) feedback. ERR is used to control the level in which a user chooses to take actions in an effort to minimize false positives.
Signatures once stored in NVRAM, will now be stored in the delta configuration file; thus, support for access control lists (ACLs) is no longer necessary.
Additional Risk Rating Algorithims
The ERR characterizes the risk of an attack and allows users to make decisions on the basis of the risk control signature event actions. To help further control signature event actions, the following additional rating categories are now supported:
•
Attack Severity Rating (ASR)—Determines the severity of an attack. The attack-severity rating values are hard-coded in Cisco IOS IPS as follows: high, medium, low, and informational. The ASR can be changed via the alert-rating command. To change the ASF, see the section "Tuning Signature Parameters."
•
Signature Fidelity Rating (SFR)—Determines the confidence level of detecting a true positive. The SFR can be changed via the fidelity-rating command. To change the SFR, see the section "Tuning Signature Parameters."
•
Target Value Rating (TVR)—Allows users to develop security policies that can be more strict for some resources than others. The security policy is applied to a table of hosts that are protected by Cisco IOS IPS. A host can be a single IP address or a range of IP addresses with an associated target value rating. To configure the TVR, see the task "Setting the Target Value Rating."
Benefits of Cisco IOS 5.x Format Signatures with Cisco IOS IPS
Automatic Signature Update
With Cisco IOS IPS 5.0, customers can now configure automatic signature updates from local servers.
Network administrators can either preserve the user's current configuration of signature actions or override the user's current configuration of signature actions with the current IPS configuration.
Auto update can also update the CLI signature package.
If this feature is enabled, signatures are delivered in either a Basic signature file or an Advanced signature file.
Signature Category-Based Configuration
Top-level signature categories help to classify signatures for easy grouping and tuning; that is, group-wide parameters, such as signature event action, can be applied to a group via CLI, so the user does not have to modify each individual signature.
Encrypted Signature Support
Cisco IOS IPS introduces support for encrypted (NDA) signatures.
Signature Update Accessibility
To help detect the latest vulnerabilities, Cisco provides the following signature update options:
•
Download the latest signature file package from Cisco.com at the following URL:
http://www.cisco.com/cgi-bin/tablebuild.pl/ios-v5sigup
•
Configure automatic signature updates via the ip ips autoupdate command. Updates can be configured to run on the basis of a preset time. For more information, see the task "Enabling Automatic Signature Updates."
•
Issue the copy url idconf command to instruct the router where to load a signature file. (The file can be saved in a location specified via the ip ips config location command.)
How to Use Cisco IOS 5.x Format Signatures with Cisco IOS IPS
This section contains the following procedures:
•
Retiring All Signatures and Selecting a Category of Signatures
•
Configuring Cisco IOS IPS on Your Router
•
Loading a Signature File into Cisco IOS IPS
•
Setting the Target Value Rating
•
Enabling Automatic Signature Updates
•
Monitoring Cisco IOS IPS Signatures via Syslog Messages or SDEE
Retiring All Signatures and Selecting a Category of Signatures
Router memory and resource constraints prevent a router from loading all Cisco IOS IPS signatures. Thus, it is recommended that you load only a selected set of signatures that are defined by the categories. Because the categories are applied in a "top-down" order, you should first retire all signatures, followed by "unretiring" specific categories. Retiring signatures enables the router to load information for all signatures, but the router will not build the parallel scanning data structure.
Retired signatures are not scanned by Cisco IOS IPS, so they will not fire alarms. If a signature is irrelevant to your network or if you want to save router memory, you should retire signatures, as appropriate.
SUMMARY STEPS
1.
enable
2.
configure terminal
3.
ip ips signature-category
4.
category category [sub-category]
5.
retired {true | false}
6.
exit
7.
category category [sub-category]
8.
retired {true | false}
9.
exit
DETAILED STEPS
What to Do Next
After you have configured the basic category, you should enable Cisco IOS IPS on your router as shown in the section "Configuring Cisco IOS IPS on Your Router."
You can customize (or tune) the entire category or individual signatures within a category to addresses the needs of your network. For information on tuning signatures, see the section "Tuning Signature Parameters."
Configuring Cisco IOS IPS on Your Router
After you have set up a "load definition" for the signature package file to be copied to the idconf, you must configure an IPS rule name. Use this task to configure an IPS rule name and start the IPS configuration.
You can also use this task to configure a Cisco IOS IPS signature location, which tells Cisco IOS IPS where to save signature information.
The configuration location is used to restore the IPS configuration in case the router reboots or IPS is disabled or reenabled. Files, such as signature definition, signature-type definitions, and signature category information, are written in XML format, compressed, and saved to the specified IPS signature location.
SUMMARY STEPS
1.
enable
2.
mkdir flash:/ips5
3.
configure terminal
4.
ip ips name ips-name
5.
ip ips config location url
6.
interface type name
7.
ip ips ips-name {in | out}
8.
exit
9.
show ip ips configuration
10.
show ip ips signature count
DETAILED STEPS
Examples
The following sample output displays the number of signatures that have been loaded into each SME:
Router# show ip ips signature count
Cisco SDF release version S247.0Trend SDF release version V1.2Signature Micro-Engine: multi-stringTotal Signatures: 7Enabled: 7Retired: 2Compiled: 5Signature Micro-Engine: service-httpTotal Signatures: 541Enabled: 284Retired: 336Compiled: 205Signature Micro-Engine: string-tcpTotal Signatures: 487Enabled: 332Retired: 352Compiled: 135Signature Micro-Engine: string-udpTotal Signatures: 50Enabled: 3Retired: 23Compiled: 27Signature Micro-Engine: stateTotal Signatures: 26Enabled: 15Retired: 23Compiled: 3Signature Micro-Engine: atomic-ipTotal Signatures: 140Enabled: 87Retired: 93Compiled: 46Inactive - invalid params: 1Signature Micro-Engine: string-icmpTotal Signatures: 2Enabled: 0Retired: 1Compiled: 1Signature Micro-Engine: service-ftpTotal Signatures: 3Enabled: 3Compiled: 3Signature Micro-Engine: service-rpc (INACTIVE)Signature Micro-Engine: service-dnsTotal Signatures: 1Enabled: 1Retired: 1Signature Micro-Engine: normalizerTotal Signatures: 9Enabled: 9Compiled: 9Total Signatures: 1266Total Enabled Signatures: 741Total Retired Signatures: 831Total Compiled Signatures: 434Total Signatures with invalid parameters: 1Loading a Signature File into Cisco IOS IPS
Use this task to load a signature package into Cisco IOS IPS. You may wish to load a new signature package into Cisco IOS IPS if a signature (or signatures) with the current signature package is not providing your network with adequate protection from security threats.
Prerequisites
You must enable Cisco IOS IPS (as shown in the task "Configuring Cisco IOS IPS on Your Router") before loading a new signature package.
Flexible Signatures: Ordered and Incremental
Each signature is complied incrementally into the scanning tables at the same time. Thus, Cisco IOS IPS can deactivate signatures that fail to compile. (Prior to Cisco IOS Release 12.4(11)T, Cisco IOS IPS deactivated the entire signature microengine (SME) if a single signature failed to compile.)
Signatures are loaded into the scanning table on the basis of importance. Parameters such as signature severity, signature fidelity rating, and time lapsed since signatures were last released allow Cisco IOS IPS to compile the most important signatures first, followed by less important signatures, thereby, creating a load order and prioritizing which signatures are loaded first.
SUMMARY STEPS
1.
enable
2.
configure terminal
3.
ip ips config location url
4.
interface type name
5.
ip ips ips-name {in | out}
6.
exit
7.
copy url idconf
DETAILED STEPS
Tuning Signature Parameters
You can tune signature parameters on the basis of a signature ID (for an individual signature), or you can tune signature parameters on the basis of a category (that is, all signatures that are within a specified category). To tune signature parameters, use the following tasks, as appropriate:
•
Tuning Signatures Per Signature ID
•
Tuning Signatures Per Category
Note
Some changes to the signature definitions are not shown in the run time config because the changes are recorded in the sigdef-delta.xml file, which can be located via the ip ips config location command.
Tuning Signatures Per Signature ID
Use this task to change default signature parameters for a specified signature ID.
SUMMARY STEPS
1.
enable
2.
configure terminal
3.
ip ips signature-definition
4.
signature signature-id [subsignature-id]
5.
engine
6.
event-action action
7.
exit
8.
alert-severity {high | medium | low | informational}
9.
fidelity-rating rating
10.
status
11.
enabled {true | false}
12.
exit
13.
show ip ips signature
DETAILED STEPS
Tuning Signatures Per Category
Use this task to change default signature parameters for a category of signatures. Categories such as operating systems; Layer 2, Layer 3, or Layer 4 protocols; or service-based categories can be configured to provide wider changes to a group of signatures.
Tip
Category configuration information is processed in the order that it is entered. Thus, it is recommended that the process of retiring all signatures (as shown in the task "Retiring All Signatures and Selecting a Category of Signatures") occur before all other category tuning.
If a category is configured more than once, the parameters entered in the second configuration will be added to or will replace the previous configuration.
SUMMARY STEPS
1.
enable
2.
configure terminal
3.
ip ips signature-category
4.
category category [sub-category]
5.
event-action action
6.
alert-severity {high | medium | low | informational}
7.
fidelity-rating rating
8.
enabled {true | false}
9.
retired {true | false}
10.
exit
11.
show ip ips signature
DETAILED STEPS
Setting the Target Value Rating
Use this task to set the target value rating, which allows users to develop security policies that can be more strict for some resources than others. The security policy is applied to a table of hosts that are protected by Cisco IOS IPS. A host can be a single IP address or a range of IP addresses with an associated target value rating.
Note
Changes to the target value rating is not shown in the run time config because the changes are recorded in the seap-delta.xml file, which can be located via the ip ips config location command.
SUMMARY STEPS
1.
enable
2.
configure terminal
3.
ip ips event-action-rules
4.
target-value {mission-critical | high | medium | low} target-address ip-address [/nn | to ip-address]
5.
exit
DETAILED STEPS
Enabling Automatic Signature Updates
Automatic signature updates allow users to override the existing configuration and automatically keep signatures up to date on the basis of a preset time, which can be configured to a preferred setting.
Time can be updated via the hardware clock or the configurable software clock (which ever option is available on your system). Although Network Time Protocol (NTP) is typically used for automated time synchronization, Cisco IOS IPS updates use the local clock resources as a reference for update intervals. Thus, NTP should be configured to update the local time server of the router, as appropriate.
Use this task to enable Cisco IOS IPS to automatically update the signature file on the system.
Automatic Signature Update Guidelines
When enabling automatic signature updates, it is recommended that you ensure the following configuration guidelines have been met:
•
The router's clock is set up with the proper relative time.
•
The frequency for Cisco IOS IPS to obtain updated signature information has been defined.
•
The URL in which to retrieve the Cisco IOS IPS signature configuration files has been specified.
•
Optionally, the username and password for which to access the files from the server have been specified.
SUMMARY STEPS
1.
enable
2.
configure terminal
3.
ip ips auto-update
4.
occur-at min:hour date day
5.
username name password password
6.
url url
7.
exit
8.
show ip ips auto-update
DETAILED STEPS
Examples
The following example shows how to configure automatic signature updates and issue the show ip ips auto-update command to verify the configuration. In this example, the signature package file is pulled from the TFTP server at the start of every hour or every day, Sunday through Thursday. (Note that adjustments are made for months without 31 days and daylight savings time.)
Router# clock set ?
hh:mm:ss Current TimeRouter# clock set 10:38:00 20 apr 2006
Router#*Apr 20 17:38:00.000: %SYS-6-CLOCKUPDATE: System clock has been updated from 10:37:55 MST Thu Apr 20 2006 to 10:38:00 MST Thu Apr 20 2006, configured from console by cisco on console.Router(config)# ip ips auto-update
Router(config-ips-auto-update)# occur-at 0 0-23 1-31 1-5
Router(config-ips-auto-update)# $s-auto-update/IOS_reqSeq-dw.xml
Router(config-ips-auto-update)#^Z
Router#*May 4 2006 15:50:28 MST: IPS Auto Update: setting update timer for next update: 0 hrs 10 min*May 4 2006 15:50:28 MST: %SYS-5-CONFIG_I: Configured from console by cisco on consoleRouter#Router# show ip ips auto-update
IPS Auto Update ConfigurationURL : tftp://192.168.0.2/jdoe/ips-auto-update/IOS_reqSeq-dw.xmlUsername : not configuredPassword : not configuredAuto Update Intervalsminutes (0-59) : 0hours (0-23) : 0-23days of month (1-31) : 1-31days of week: (0-6) : 1-5Monitoring Cisco IOS IPS Signatures via Syslog Messages or SDEE
Cisco IOS IPS provides two methods to report IPS intrusion alerts—Cisco IOS logging (syslog) and SDEE. Perform this task to enable SDEE to report IPS intrusion alerts.
To configure syslog messages, see the chapter "Troubleshooting and Fault Management" in the Cisco IOS Network Management Configuration Guide, Release 12.4.
SDEE Overview
SDEE is an application-level communication protocol that is used to exchange IPS messages between IPS clients and IPS servers. SDEE is always running, but it does not receive and process events from IPS unless SDEE notification is enabled. If SDEE notification is not enabled and a client sends a request, SDEE will respond with a fault response message, indicating that notification is not enabled.
Storing SDEE Events in the Buffer
When SDEE notification is enabled (via the ip ips notify sdee command), 200 events can automatically be stored in the buffer. When SDEE notification is disabled, all stored events are lost. A new buffer is allocated when the notifications are reenabled.
When specifying the size of an events buffer, note the following functionality:
•
It is circular. When the end of the buffer is reached, the buffer will start overwriting the earliest stored events. (If overwritten events have not yet been reported, you will receive a buffer overflow notice.)
•
If a new, smaller buffer is requested, all events that are stored in the previous buffer will be lost.
•
If a new, larger buffer is requested, all existing events will be saved.
Prerequisites
To use SDEE, the HTTP server must be enabled (via the ip http server command). If the HTTP server is not enabled, the router cannot respond to the SDEE clients because it cannot not "see" the requests.
SUMMARY STEPS
1.
enable
2.
configure terminal
3.
ip ips notify sdee
4.
ip sdee events events
5.
ip sdee subscriptions subscriptions
6.
ip sdee messages messages
7.
ip sdee alerts alerts
8.
exit
9.
show ip sdee {[alerts] [all] [errors] [events] [configuration] [status] [subscriptions]}
DETAILED STEPS
Examples
The following example shows how to configure and verify SDEE on your router:
Router(config)# ip ips notify SDEE
Router(config)# ip sdee event 500
Router(config)# ip sdee subscriptions 1
Router(config)# ip sdee messages 500
Router(config)# ip sdee alerts 2000
router(config)# exit
*Nov 9 21:41:33.171: %SYS-5-CONFIG_I: Configured from console by cisco on consoleRouter# show ip sdee all
Configured concurrent subscriptions: 1No currently open subscriptions.Alert storage: 2000 alerts using 560000 bytes of memoryMessage storage: 500 messages using 212000 bytes of memorySDEE EventsTime Type DescriptionRouter#Troubleshooting Tips
To print out new SDEE alerts on the router console, issue the debug ip sdee command.
To clear the event buffer or SDEE subscriptions from the router (which helps with error recovery), issue the clear ip sdee command.
Configuration Examples
This section contains the following configuration example:
•
Cisco IOS IPS Configuration: Example
Cisco IOS IPS Configuration: Example
The following example shows how to enable and verify Cisco IOS IPS on your router:
Router# mkdir flash:/ips5
Create directory filename [ips5]?Created dir flash:/ips5Router#Router#Router#Router# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.Router(config)# ip ips name MYIPS
Router(config)# ip ips config location flash:/ips5
Router(config)# ip ips signature-category
Router(config-ips-category)# category all
Router(config-ips-category-action)# retired true
Router(config-ips-category-action)# exit
Router(config-ips-category)# category ios_ips advanced
Router(config-ips-category-action)# retired false
Router(config-ips-category-action)# exit
Router(config-ips-category)# exit
Do you want to accept these changes? [confirm]Router(config)# d*Nov 14 2006 17:16:42 MST: Applying Category configuration to signatures ..Router(config)#Router(config)# do show ip interface brief
Interface IP-Address OK? Method Status ProtocolGigabitEthernet0/0 10.0.20.120 YES NVRAM up upGigabitEthernet0/1 10.12.100.120 YES NVRAM administratively down downNVI0 unassigned NO unset up upRouter(config)#Router(config)# interface gigabits 0/0
Router(config-if)# ip ips MYIPS in
Router(config-if)#*Nov 14 2006 17:17:07 MST: %IPS-6-ENGINE_BUILDS_STARTED: 17:17:07 MST Nov 14 2006*Nov 14 2006 17:17:07 MST: %IPS-6-ENGINE_BUILDING: atomic-ip - 3 signatures - 1 of 13 engines*Nov 14 2006 17:17:07 MST: %IPS-6-ENGINE_READY: atomic-ip - build time 0 ms - packets for this engine will be scanned*Nov 14 2006 17:17:07 MST: %IPS-6-ALL_ENGINE_BUILDS_COMPLETE: elapsed time 0 msRouter(config-if)#Router(config-if)# ip ips MYIPS out
Router(config-if)#Router(config-if)#Router(config-if)#^Z
Router#*Nov 14 2006 17:17:23 MST: %SYS-5-CONFIG_I: Configured from console by cisco on consoleRouter# wrBuilding configuration...[OK]Router#Router# show ip ips signature count
Cisco SDF release version S0.0Signature Micro-Engine: multi-string (INACTIVE)Signature Micro-Engine: service-http (INACTIVE)Signature Micro-Engine: string-tcp (INACTIVE)Signature Micro-Engine: string-udp (INACTIVE)Signature Micro-Engine: state (INACTIVE)Signature Micro-Engine: atomic-ipTotal Signatures: 3Enabled: 0Compiled: 3Signature Micro-Engine: string-icmp (INACTIVE)Signature Micro-Engine: service-ftp (INACTIVE)Signature Micro-Engine: service-rpc (INACTIVE)Signature Micro-Engine: service-dns (INACTIVE)Signature Micro-Engine: normalizer (INACTIVE)Signature Micro-Engine: service-smb-advanced (INACTIVE)Signature Micro-Engine: service-msrpc (INACTIVE)Total Signatures: 3Total Enabled Signatures: 0Total Retired Signatures: 0Total Compiled Signatures: 3Router#Router# copy flash:IOS-S258-CLI-kd.pkg idconf
*Nov 14 2006 17:19:47 MST: %IPS-6-ENGINE_BUILDS_STARTED: 17:19:47 MST Nov 14 2006*Nov 14 2006 17:19:47 MST: %IPS-6-ENGINE_BUILDING: multi-string - 3 signatures - 1 of 13 engines*Nov 14 2006 17:19:47 MST: %IPS-6-ENGINE_READY: multi-string - build time 4 ms - packets for this engine will be scanned*Nov 14 2006 17:19:47 MST: %IPS-6-ENGINE_BUILDING: service-http - 611 signatures - 2 of 13 engines*Nov 14 2006 17:20:00 MST: %IPS-6-ENGINE_READY: service-http - build time 12932 ms - packets for this engine will be scanned*Nov 14 2006 17:20:00 MST: %IPS-6-ENGINE_BUILDING: string-tcp - 864 signatures - 3 of 13 engines*Nov 14 2006 17:20:02 MST: %IPS-6-ENGINE_READY: string-tcp - build time 2692 ms - packets for this engine will be scanned*Nov 14 2006 17:20:02 MST: %IPS-6-ENGINE_BUILDING: string-udp - 74 signatures - 4 of 13 engines*Nov 14 2006 17:20:03 MST: %IPS-6-ENGINE_READY: string-udp - build time 316 ms - packets for this engine will be scanned*Nov 14 2006 17:20:03 MST: %IPS-6-ENGINE_BUILDING: state - 28 signatures - 5 of 13 engines*Nov 14 2006 17:20:03 MST: %IPS-6-ENGINE_READY: state - build time 24 ms - packets for this engine will be scanned*Nov 14 2006 17:20:03 MST: %IPS-6-ENGINE_BUILDING: atomic-ip - 252 signatures - 6 of 13 engines*Nov 14 2006 17:20:03 MST: %IPS-4-META_ENGINE_UNSUPPORTED: atomic-ip 2154:0 - this signature is a component of the unsupported META engine*Nov 14 2006 17:20:03 MST: %IPS-6-ENGINE_READY: atomic-ip - build time 232 ms - packets for this engine will be scanned*Nov 14 2006 17:20:03 MST: %IPS-6-ENGINE_BUILDING: string-icmp - 3 signatures - 7 of 13 eRouter# engines*Nov 14 2006 17:20:03 MST: %IPS-6-ENGINE_READY: string-icmp - build time 12 ms - packets for this engine will be scanned*Nov 14 2006 17:20:03 MST: %IPS-6-ENGINE_BUILDING: service-ftp - 3 signatures - 8 of 13 engines*Nov 14 2006 17:20:03 MST: %IPS-6-ENGINE_READY: service-ftp - build time 8 ms - packets for this engine will be scanned*Nov 14 2006 17:20:03 MST: %IPS-6-ENGINE_BUILDING: service-rpc - 75 signatures - 9 of 13 engines*Nov 14 2006 17:20:03 MST: %IPS-6-ENGINE_READY: service-rpc - build time 80 ms - packets for this engine will be scanned*Nov 14 2006 17:20:03 MST: %IPS-6-ENGINE_BUILDING: service-dns - 38 signatures - 10 of 13 engines*Nov 14 2006 17:20:03 MST: %IPS-6-ENGINE_READY: service-dns - build time 20 ms - packets for this engine will be scanned*Nov 14 2006 17:20:03 MST: %IPS-6-ENGINE_BUILDING: normalizer - 9 signatures - 11 of 13 engines*Nov 14 2006 17:20:03 MST: %IPS-6-ENGINE_READY: normalizer - build time 0 ms - packets for this engine will be scanned*Nov 14 2006 17:20:03 MST: %IPS-6-ENGINE_BUILDING: service-msrpc - 22 signatures - 12 of 13 engines*Nov 14 2006 17:20:03 MST: %IPS-6-ENGINE_READY: service-msrpc - build time 8 ms - packets for this engine will be scanned*Nov 14 2006 17:20:03 MST: %IPS-6-ALL_ENGINE_BUILDS_COMPLETE: elapsed time 16344 msRouter#Router#Router# show ip ips signature count
Cisco SDF release version S258.0Signature Micro-Engine: multi-stringTotal Signatures: 3Enabled: 3Retired: 3Signature Micro-Engine: service-httpTotal Signatures: 611Enabled: 159Retired: 428Compiled: 183Signature Micro-Engine: string-tcpTotal Signatures: 864Enabled: 414Retired: 753Compiled: 111Signature Micro-Engine: string-udpTotal Signatures: 74Enabled: 1Retired: 44Compiled: 30Signature Micro-Engine: stateTotal Signatures: 28Enabled: 16Retired: 25Compiled: 3Signature Micro-Engine: atomic-ipTotal Signatures: 252Enabled: 56Retired: 148Compiled: 103Inactive - invalid params: 1Signature Micro-Engine: string-icmpTotal Signatures: 3Enabled: 0Retired: 2Compiled: 1Signature Micro-Engine: service-ftpTotal Signatures: 3Enabled: 1Compiled: 3Signature Micro-Engine: service-rpcTotal Signatures: 75Enabled: 44Retired: 44Compiled: 31Signature Micro-Engine: service-dnsTotal Signatures: 38Enabled: 30Retired: 5Compiled: 33Signature Micro-Engine: normalizerTotal Signatures: 9Enabled: 8Retired: 5Compiled: 4Signature Micro-Engine: service-smb-advanced (INACTIVE)Signature Micro-Engine: service-msrpcTotal Signatures: 22Enabled: 22Retired: 22Additional References
The following sections provide references related to the Cisco IOS IPS 5.0 Enhancements feature.
Related Documents
Related Topic Document TitleIPS and firewall
Cisco IOS Security Configuration Guide, Release 12.4
IPS and firewall commands
Cisco IOS Security Command Reference, Release 12.4T
Loading images and file systems
The chapter "Loading and Managing System Images" in the Cisco IOS Configuration Fundamentals Configuration Guide, Release 12.4
Standards
MIBs
RFCs
Technical Assistance
Command Reference
This section documents new commands only.
alert-severity
To change the alert severity rating for a given signature or signature category, use the alert-severity command in signature-definition-action (config-sigdef-action) or IPS-category-action (config-ips-category-action) configuration mode. To return to the default action, use the no form of this command.
alert-severity {high | medium | low | informational}
no alert-severity
Syntax Description
high | medium | low | informational
Alert severity action for a given signature or signature category.
Command Default
No default behavior or values
Command Modes
Signature-definition-action configuration (config-sigdef-action)
IPS-category-action configuration (config-ips-category-action)Command History
Usage Guidelines
Before issuing the alert-severity command, you must specify either a signature via the signature command or a signature category (such as attack-type) via the category command.
Examples
The following example shows how to set the alert severity value to low for signature 5760:
Router# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.Router(config)# ip ips signature-definition
Router(config-sigdef)# signature 5726 0
Router(config-sigdef-sig)# alert-severity low
Router(config-sigdef)#^ZDo you want to accept these changes? [confirm]Router#*Nov 9 21:50:55.847: %IPS-6-ENGINE_BUILDING: multi-string - 3 signatures - 12 of 11 engines*Nov 9 21:50:55.859: %IPS-6-ENGINE_READY: multi-string - build time 12 ms - packets for this engine will be scanned*Nov 9 21:50:55.859: %SYS-5-CONFIG_I: Configured from console by cisco on consoleRelated Commands
category
To specify a signature category that is to be used for multiple signature actions or conditions, use the category command in IPS-category configuration mode.
category category [sub-category]
Syntax Description
Command Default
None
Command Modes
IPS-category configuration (config-ips-category)
Command History
Usage Guidelines
Cisco IOS Intrusion Prevention System (IPS) 5.x uses signatures and signature categories. All signatures are pregrouped into categories; the categories are hierarchical. An individual signature can belong to more than one category. Top-level categories help to define general types of signatures. Subcategories exist beneath each top-level signature category.
Examples
The following example shows how to tune event-action parameters for the signature category "adware/spyware." All tuning information will be applied to all signatures that belong to the adware/spyware category.
Router(config)# ip ips signature-category
Router(config-ips-category)# category attack adware/spyware
Router(config-ips-category-action)# event-action produce-alert
Router(config-ips-category-action)# event-action deny-packet-inline
Router(config-ips-category-action)# event-action reset-tcp-connection
Router(config-ips-category-action)# retired false
Router(config-ips-category-action)# ^Z
Do you want to accept these changes? [confirm]y
Related Commands
copy idconf
To load a signature package in Cisco IOS Intrusion Prevention System (IPS), use the copy idconf command in EXEC mode.
copy url idconf
Syntax Description
Command Default
None
Command Modes
EXEC
Command History
Usage Guidelines
Use the copy url idconf command to load a signature package into Cisco IOS IPS. You may wish to load a new signature package into Cisco IOS IPS if a signature (or signatures) with the current signature file is not providing your network with adequate protection from security threats. After the signature package has been loaded into the router, Cisco IOS IPS saves all signature information to the location specified via the ip ips config location command.
Signatures are loaded into the scanning table on the basis of importance. Parameters such as signature severity, signature fidelity rating, and time lapsed since signatures were released enable Cisco IOS IPS to compile the most important signatures first, followed by less important signatures, thereby, creating a load order and prioritizing which signatures are loaded first.
Note
The copy url idconf command replaces the copy ips-sdf command.
Examples
The following example shows how to load a signature package into Cisco IOS IPS from the location "flash:IOS-S258-CLI-kd.pkg":
Router# copy flash:IOS-S258-CLI-kd.pkg idconf
*Nov 14 2006 17:19:47 MST: %IPS-6-ENGINE_BUILDS_STARTED: 17:19:47 MST Nov 14 2006*Nov 14 2006 17:19:47 MST: %IPS-6-ENGINE_BUILDING: multi-string - 3 signatures - 1 of 13 engines*Nov 14 2006 17:19:47 MST: %IPS-6-ENGINE_READY: multi-string - build time 4 ms - packets for this engine will be scanned*Nov 14 2006 17:19:47 MST: %IPS-6-ENGINE_BUILDING: service-http - 611 signatures - 2 of 13 engines*Nov 14 2006 17:20:00 MST: %IPS-6-ENGINE_READY: service-http - build time 12932 ms - packets for this engine will be scanned*Nov 14 2006 17:20:00 MST: %IPS-6-ENGINE_BUILDING: string-tcp - 864 signatures - 3 of 13 engines*Nov 14 2006 17:20:02 MST: %IPS-6-ENGINE_READY: string-tcp - build time 2692 ms - packets for this engine will be scanned*Nov 14 2006 17:20:02 MST: %IPS-6-ENGINE_BUILDING: string-udp - 74 signatures - 4 of 13 engines*Nov 14 2006 17:20:03 MST: %IPS-6-ENGINE_READY: string-udp - build time 316 ms - packets for this engine will be scanned*Nov 14 2006 17:20:03 MST: %IPS-6-ENGINE_BUILDING: state - 28 signatures - 5 of 13 engines*Nov 14 2006 17:20:03 MST: %IPS-6-ENGINE_READY: state - build time 24 ms - packets for this engine will be scanned*Nov 14 2006 17:20:03 MST: %IPS-6-ENGINE_BUILDING: atomic-ip - 252 signatures - 6 of 13 engines*Nov 14 2006 17:20:03 MST: %IPS-4-META_ENGINE_UNSUPPORTED: atomic-ip 2154:0 - this signature is a component of the unsupported META engine*Nov 14 2006 17:20:03 MST: %IPS-6-ENGINE_READY: atomic-ip - build time 232 ms - packets for this engine will be scanned*Nov 14 2006 17:20:03 MST: %IPS-6-ENGINE_BUILDING: string-icmp - 3 signatures - 7 of 13 eRouter# engines*Nov 14 2006 17:20:03 MST: %IPS-6-ENGINE_READY: string-icmp - build time 12 ms - packets for this engine will be scanned*Nov 14 2006 17:20:03 MST: %IPS-6-ENGINE_BUILDING: service-ftp - 3 signatures - 8 of 13 engines*Nov 14 2006 17:20:03 MST: %IPS-6-ENGINE_READY: service-ftp - build time 8 ms - packets for this engine will be scanned*Nov 14 2006 17:20:03 MST: %IPS-6-ENGINE_BUILDING: service-rpc - 75 signatures - 9 of 13 engines*Nov 14 2006 17:20:03 MST: %IPS-6-ENGINE_READY: service-rpc - build time 80 ms - packets for this engine will be scanned*Nov 14 2006 17:20:03 MST: %IPS-6-ENGINE_BUILDING: service-dns - 38 signatures - 10 of 13 engines*Nov 14 2006 17:20:03 MST: %IPS-6-ENGINE_READY: service-dns - build time 20 ms - packets for this engine will be scanned*Nov 14 2006 17:20:03 MST: %IPS-6-ENGINE_BUILDING: normalizer - 9 signatures - 11 of 13 engines*Nov 14 2006 17:20:03 MST: %IPS-6-ENGINE_READY: normalizer - build time 0 ms - packets for this engine will be scanned*Nov 14 2006 17:20:03 MST: %IPS-6-ENGINE_BUILDING: service-msrpc - 22 signatures - 12 of 13 engines*Nov 14 2006 17:20:03 MST: %IPS-6-ENGINE_READY: service-msrpc - build time 8 ms - packets for this engine will be scanned*Nov 14 2006 17:20:03 MST: %IPS-6-ALL_ENGINE_BUILDS_COMPLETE: elapsed time 16344 msRelated Commands
Command Descriptionip ips config-location
Specifies the location in which the router will save signature information.
enabled (IPS)
To change the enabled status of a given signature or signature category, use the enabled command in signature-definition-status (config-sigdef-status) or IPS-category-action (config-ips-category-action) configuration mode. To return to the default action, use the no form of this command.
enabled {true | false}
no enabled
Syntax Description
true
Enables a specified signature or all signatures within a specified category.
false
Disables a specified signature or all signatures within a specified category.
Command Default
All commands are enabled.
Command Modes
Signature-definition-status configuration (config-sigdef-status)
IPS-category-action configuration (config-ips-category-action)Command History
Usage Guidelines
Use the enabled command to change the status of a signature or signature category to active (true) or inactive (false).
Examples
The following example shows how to change the status of signature 9000:0 to enabled:
Router(config)# ip ips signature-definition
Router(config-sig)# signature 9000 0
Router(config-sig-sig)# status
Router(config-sigdef-status)# enabled true
Related Commands
engine (IPS)
To enter signature-definition-action-engine configuration mode, which allows you to change router actions for a specified signature, use the engine command in signature-definition-action configuration mode.
engine
Syntax Description
This command has no arguments or keywords.
Command Default
None
Command Modes
Signature-definition-action configuration (config-sigdef-action)
Command History
Usage Guidelines
If you wish to change router actions for a specific signature, you must issue the engine command to enter the appropriate configuration mode, which allows you to issue the event-action command and specify any supported action.
Examples
The following example shows how to configure signature 5726 to reset all TCP connections and produce an alert:
Router# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.Router(config)# ip ips signature-definition
Router(config-sigdef)# signature 5726 0
Router(config-sigdef-sig)# engine
Router(config-sigdef-sig-engine)# event-action reset-tcp-connection produce-alert
Router(config-sigdef-sig-engine)# exit
Router(config-sigdef-sig)# exit
Router(config-sigdef)#^ZDo you want to accept these changes? [confirm]Router#*Nov 9 21:50:55.847: %IPS-6-ENGINE_BUILDING: multi-string - 3 signatures - 12 of 11 engines*Nov 9 21:50:55.859: %IPS-6-ENGINE_READY: multi-string - build time 12 ms - packets for this engine will be scanned*Nov 9 21:50:55.859: %SYS-5-CONFIG_I: Configured from console by cisco on consoleRelated Commands
Command Descriptionevent-action
Changes router actions for a signature or signature category.
signature
Specifies a signature for which the CLI user tunings will be changed.
event-action
To change router actions for a signature or signature category, use the event-action command in signature-definition-action-engine or IPS-category-action configuration mode. To revert to the default router action values, use the no form of this command.
event-action action
no event-action
Syntax Description
Command Default
Default values for the signature or signature category will be used.
Command Modes
Signature-definition-action-engine configuration (config-sigdef-action-engine)
IPS-category-action configuration (config-ips-category-action)Command History
Usage Guidelines
Signature-Based Changes
After signature-based changes are complete, Cisco IOS Intrusion Prevention System (IPS) prompts the user to confirm whether or not the changes are acceptable. Confirming the changes instructs Cisco IOS IPS to compile the changes for the signature and modify memory structures to reflect the change. Also, Cisco IOS IPS will save the changes to the location specified via the ip ips config location command (for example, flash:ips5/*.xml).
You can issue the show ip ips signatures command to verify the event-action configuration. (The show running-config command does not show individual signature tuning information.)
Signature Category-Based Changes
After signature category-based changes are complete, the category tuning information is saved in the command-line interface (CLI) configuration.
Category configuration information is processed in the order that it is entered. Thus, it is recommended that the process of retiring all signatures occur before all other category tuning.
If a category is configured more than once, the parameters entered in the second configuration will be added to or will replace the previous configuration.
Examples
The following example shows how to configure signature 5726 to reset all TCP connections and produce an alert:
Router# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.Router(config)# ip ips signature-definition
Router(config-sigdef)# signature 5726 0
Router(config-sigdef-sig)# engine
Router(config-sigdef-sig-engine)# event-action reset-tcp-connection produce-alert
Router(config-sigdef-sig-engine)# exit
Router(config-sigdef-sig)# exit
Router(config-sigdef)#^ZDo you want to accept these changes? [confirm]Router#*Nov 9 21:50:55.847: %IPS-6-ENGINE_BUILDING: multi-string - 3 signatures - 12 of 11 engines*Nov 9 21:50:55.859: %IPS-6-ENGINE_READY: multi-string - build time 12 ms - packets for this engine will be scanned*Nov 9 21:50:55.859: %SYS-5-CONFIG_I: Configured from console by cisco on consoleThe following example shows how to tune event-action parameters for the signature category "adware/spyware." All the tuning information will be applied to all signatures that belong to the adware/spyware signature category.
Router(config)# ip ips signature category
Router(config-ips-category)# category attack adware/spyware
Router(config-ips-category-action)# event-action produce-alert
Router(config-ips-category-action)# event-action deny-packet-inline
Router(config-ips-category-action)# event-action reset-tcp-connection
Router(config-ips-category-action)# retired false
Router(config-ips-category-action)# ^Z
Do you want to accept these changes:[confirmm]y
Related Commands
fidelity-rating
To change the signature fidelity rating for a given signature or signature category, use the fidelity-rating command in signature-definition-action (config-sigdef-action) or IPS-category-action (config-ips-category-action) configuration mode. To return to the default action, use the no form of this command.
fidelity-rating rating
no fidelity-rating
Syntax Description
Command Default
The default value is defined in the signature definition XML.
Command Modes
Signature-definition-action configuration (config-sigdef-action)
IPS-category-action configuration (config-ips-category-action)Command History
Usage Guidelines
A signature's fidelity rating is a rating of the confidence level of detecting a true positive. It can be viewed as a quality rating for the signature.
Examples
The following example shows how to set the fidelity rating to zero for signature 5726:
Router# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.Router(config)# ip ips signature-definition
Router(config-sigdef)# signature 5726 0
Router(config-sigdef-sig)# fidelity-rating 0
Router(config-sigdef)# ^ZDo you want to accept these changes? [confirm]Router#*Nov 9 21:50:55.847: %IPS-6-ENGINE_BUILDING: multi-string - 3 signatures - 12 of 11 engines*Nov 9 21:50:55.859: %IPS-6-ENGINE_READY: multi-string - build time 12 ms - packets for this engine will be scanned*Nov 9 21:50:55.859: %SYS-5-CONFIG_I: Configured from console by cisco on consoleRelated Commands
ip ips auto-update
To enable automatic signature updates for Cisco IOS Intrusion Prevention System (IPS), use the ip ips auto-update command in global configuration mode. To revert back to the default value, use the no form of this command.
ip ips auto-update
no ip ips auto-update
Syntax Description
This command has no arguments or keywords.
Command Default
The default value is defined in the signature definition XML.
Command Modes
Global configuration
Command History
Usage Guidelines
Automatic signature updates allow users to override the existing IPS configuration and automatically keep signatures up to date on the basis of a preset time, which can be configured to a preferred setting.
Use the ip ips auto-update command to enable Cisco IOS IPS to automatically update the signature file on the system. When enabling automatic signature updates, it is recommended that you ensure the following configuration guidelines have been met:
•
The router's clock is set up with the proper relative time.
•
The frequency for Cisco IOS IPS to obtain updated signature information has been defined (via the occur-at command).
•
The URL in which to retrieve the Cisco IOS IPS signature configuration files has been specified (via the url command).
•
Optionally, the username and password in which to access the files from the server has been specified (via the username command).
If this feature is enabled, signatures are delivered in either a Basic signature file or an Advanced signature file.
The Default Value
A user or a management station can override the default value via the category command or the signature command; a value set with either of these commands will be saved as the delta value. The no form of the ip ips auto-update command will remove the delta value and revert back to the default value in the definition XML.
Setting Time for Auto Updates
Cisco IOS time can be updated via the hardware clock or the software configurable clock (which ever option is available on your system). Although Network Time Protocol (NTP) is typically used for automated time synchronization, Cisco IOS IPS updates use the local clock resources as a reference for update intervals. Thus, NTP should be configured to update the local time server of the router, as appropriate.
Examples
The following example shows how to configure automatic signature updates and issue the show ip ips auto-update command to verify the configuration. In this example, the signature package file is pulled from the TFTP server at the start of every hour or every day, Sunday through Thursday. (Note that adjustments are made for months without 31 days and daylight savings time.)
Router# clock set ?
hh:mm:ss Current TimeRouter# clock set 10:38:00 20 apr 2006
Router#*Apr 20 17:38:00.000: %SYS-6-CLOCKUPDATE: System clock has been updated from 10:37:55 MST Thu Apr 20 2006 to 10:38:00 MST Thu Apr 20 2006, configured from console by cisco on console.Router(config)# ip ips auto-update
Router(config-ips-auto-update)# occur-at 0 0-23 1-31 1-5
Router(config-ips-auto-update)# $s-auto-update/IOS_reqSeq-dw.xml
Router(config-ips-auto-update)#^Z
Router#*May 4 2006 15:50:28 MST: IPS Auto Update: setting update timer for next update: 0 hrs 10 min*May 4 2006 15:50:28 MST: %SYS-5-CONFIG_I: Configured from console by cisco on consoleRouter#Router# show ip ips auto-update
IPS Auto Update ConfigurationURL : tftp://192.168.0.2/jdoe/ips-auto-update/IOS_reqSeq-dw.xmlUsername : not configuredPassword : not configuredAuto Update Intervalsminutes (0-59) : 0hours (0-23) : 0-23days of month (1-31) : 1-31days of week: (0-6) : 1-5Related Commands
ip ips config location
To specify the location in which the router will save signature information, use the ip ips config location command in global configuration mode. To remove the specified location, use the no form of this command.
ip ips config location url
no ip ips config location
Syntax Description
Command Default
No default behavior or values. (Configuration files are saved.)
Command Modes
Global configuration
Command History
Usage Guidelines
Before configuring the ip ips config location command, you must create a directory for the config location via the mkdir command.
The ip ips config location command configures a Cisco IOS Intrusion Prevention System (IPS) signature location, which tells Cisco IOS IPS where to save signature information.
The configuration location is used to restore the IPS configuration in cases such as router reboots or IPS becoming disabled or reenabled. Files, such as signature definitions, signature-type definitions, and signature category information, are written in XML format, compressed, and saved to the specified IPS signature location.
Note
If a location is not specified, or if a location is removed via the no form, no files will be saved.
Note
The ip ips config location command replaces the ip ips sdf location command.
Examples
The following example shows how to instruct the router to save all signature information to the directory "flash:/ips5":
Router# mkdir flash:/ips5
Create directory filename [ips5]?Created dir flash:/ips5Router#Router#Router#Router# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.Router(config)# ip ips name MYIPS
Router(config)# ip ips config location flash:/ips5
Router(config)# ip ips signature-category
Router(config-ips-category)# category all
Router(config-ips-category-action)# retired true
Router(config-ips-category-action)# exit
Router(config-ips-category)# category ios_ips advanced
Router(config-ips-category-action)# retired false
Router(config-ips-category-action)# exit
Router(config-ips-category)# exit
Do you want to accept these changes? [confirm]Router(config)# d*Nov 14 2006 17:16:42 MST: Applying Category configuration to signatures ..Router(config)#ip ips event-action-rules
To enter config-rule configuration mode, which allows users to change the target value rating, use the ip ips event-action-rules command in global configuration mode.
ip ips event-action-rules
Syntax Description
This command has no arguments or keywords.
Command Default
None
Command Modes
Global configuration
Command History
Usage Guidelines
You must issue the ip ips event-action-rules command to define the target value rating via the target-value command.
Examples
The following example shows how to change the target value to low for the host 192.168.0.1:
configure terminalip ips event-action-rulestarget-value low target-address 192.168.0.1Related Commands
ip ips signature-category
To enter IPS category (config-ips-category) configuration mode, which allows you to tune Cisco IOS Intrusion Prevention System (IPS) signature parameters on the basis of a signature category, use the ip ips signature-category command in global configuration mode.
ip ips signature-category
Syntax Description
This command has no arguments or keywords.
Command Default
None
Command Modes
Global configuration
Command History
Usage Guidelines
Use the ip ips signature-category command if you want to tune signature parameters per category.
Examples
The following example shows how to tune event-action parameters for the signature category "adware/spyware." All tuning information will be applied to all signatures that belong to the adware/spyware category.
Router(config)# ip ips signature-category
Router(config-ips-category)# category attack adware/spyware
Router(config-ips-category-action)# event-action produce-alert
Router(config-ips-category-action)# event-action deny-packet-inline
Router(config-ips-category-action)# event-action reset-tcp-connection
Router(config-ips-category-action)# retired false
Router(config-ips-category-action)# ^Z
Do you want to accept these changes? [confirm]y
Related Commands
Command Descriptioncategory
Specifies a signature category that is to be used for multiple signature actions or conditions.
ip ips signature-definition
To enter signature-definition-signature configuration mode, which allows you to define a signature for command-line interface (CLI) user tunings, use the ip ips signature-definition command in global configuration mode. To revert back to the default value, use the no form of this command.
ip ips signature-definition
no ip ips signature-definition
Syntax Description
This command has no arguments or keywords.
Command Default
Signature parameters cannot be defined and default values are used.
Command Modes
Global configuration
Command History
Usage Guidelines
Use the ip ips signature-definition command to enter signature-definition-signature configuration mode, which allows you to issue the signature command. The signature command is used to specify a signature whose CLI user tunings are to be customized. After you issue the signature command, you can begin to specify which signature parameters (user tunings) are to be changed.
Examples
The following example shows how to modify signature 5081/0 to "produce alert" and "reset tcp connection":
Router(config)# ip ips signature-definition
Router(config-sigdef-sig)# signature 5081 0
Router(config-sigdef-action)# engine
Router(config-sigdef-action-engine)# event-action produce-alert reset-tcp-connection
Router(config-sigdef-action-engine)# ^Z
Do you want to accept these changes:[confirmm]y
Related Commands
occur-at (ips-auto-update)
To define the frequency in which Cisco IOS Intrusion Prevention System (IPS) obtains updated signature information, use the occur-at command in IPS-auto-update configuration mode.
occur-at min:hour date day
Syntax Description
min:hour date day
Frequency (in minutes: hour, date, and day) in which automatic signature updates occur.
Command Default
The default value is defined in the signature definition XML.
Command Modes
IPS-auto-update configuration
Command History
Usage Guidelines
Automatic signature updates allow users to override the existing IPS configuration and automatically keep signatures up to date on the basis of a preset time, which can be configured to a preferred setting.
Use the ip ips auto-update command to enable Cisco IOS IPS to automatically update the signature file on the system. Thereafter, issue the occur-at command to define how often the Cisco IOS IPS signature files should be automatically updated.
Examples
The following example shows how to configure automatic signature updates and set the frequency in which updates are made. In this example, the signature package file is pulled from the TFTP server at the start of every hour or every day, Sunday through Thursday. (Note that adjustments are made for months without 31 days and daylight savings time.)
Router# clock set ?
hh:mm:ss Current TimeRouter# clock set 10:38:00 20 apr 2006
Router#*Apr 20 17:38:00.000: %SYS-6-CLOCKUPDATE: System clock has been updated from 10:37:55 MST Thu Apr 20 2006 to 10:38:00 MST Thu Apr 20 2006, configured from console by cisco on console.Router(config)# ip ips auto-update
Router(config-ips-auto-update)# occur-at 0 0-23 1-31 1-5
Router(config-ips-auto-update)# $s-auto-update/IOS_reqSeq-dw.xml
Router(config-ips-auto-update)#^Z
Router#*May 4 2006 15:50:28 MST: IPS Auto Update: setting update timer for next update: 0 hrs 10 min*May 4 2006 15:50:28 MST: %SYS-5-CONFIG_I: Configured from console by cisco on consoleRouter#Router# show ip ips auto-update
IPS Auto Update ConfigurationURL : tftp://192.168.0.2/jdoe/ips-auto-update/IOS_reqSeq-dw.xmlUsername : not configuredPassword : not configuredAuto Update Intervalsminutes (0-59) : 0hours (0-23) : 0-23days of month (1-31) : 1-31days of week: (0-6) : 1-5Related Commands
retired (IPS)
To specify whether or not a retired signature or signature category definition should be saved in the router memory, use the retired command in signature-definition-status (config-sigdef-status) or IPS-category-action (config-ips-category-action) configuration mode. To return to the default action, use the no form of this command.
retired {true | false}
no retired
Syntax Description
true
Retires all signatures within a given category.
false
"Unretires" all signatures within a given category.
Command Default
Signature or signature category definitions are not saved in the system.
Command Modes
Signature-definition-status configuration (config-sigdef-status)
IPS-category-action configuration (config-ips-category-action)Command History
Usage Guidelines
Router memory and resource constraints prevent a router from loading all Cisco IOS IPS signatures. Thus, it is recommended that you load only a selected set of signatures that are defined by the categories. Because the categories are applied in a "top-down" order, you should first retire all signatures, followed by "unretiring" specific categories. Retiring signatures enables the router to load information for all signatures, but the router will not build the parallel scanning data structure.
Retired signatures are not scanned by Cisco IOS IPS, so they will not fire alarms. If a signature is irrelevant to your network or if you want to save router memory, you should retire signatures, as appropriate.
Examples
The following example shows how to retire all signatures and configure the Basic "ios_ips" category:
Router# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.Router(config)# ip ips signature category
Router(config-ips-category)# category all
Router(config-ips-category-action)# retired true
Router(config-ips-category-action)# exit
Router(config-ips-category)# category ios_ips basic
Router(config-ips-category-action)# retired false
Router(config-ips-category-action)# exit
Router(config-ips-category)# exit
Do you want to accept these changes? [confirm]y
Related Commands
show ip ips auto-update
To display the automatic signature update configuration, use the show ip ips auto-update command in EXEC mode.
show ip ips auto-update
Syntax Description
This command has no arguments or keywords.
Command Default
None
Command Modes
EXEC
Command History
Usage Guidelines
Automatic signature updates allow users to override the existing Intrusion Prevention System (IPS) configuration and automatically keep signatures up to date on the basis of a preset time, which can be configured to a preferred setting.
Use the show ip ips auto-update command to verify the auto update configuration.
Examples
The following example shows how to configure automatic signature updates and issue the show ip ips auto-update command to verify the configuration. In this example, the signature package file is pulled from the TFTP server at the start of every hour or every day, Sunday through Thursday. (Note that adjustments are made for months without 31 days and daylight savings time.)
Router# clock set ?
hh:mm:ss Current TimeRouter# clock set 10:38:00 20 apr 2006
Router#*Apr 20 17:38:00.000: %SYS-6-CLOCKUPDATE: System clock has been updated from 10:37:55 MST Thu Apr 20 2006 to 10:38:00 MST Thu Apr 20 2006, configured from console by cisco on console.Router(config)# ip ips auto-update
Router(config-ips-auto-update)# occur-at 0 0-23 1-31 1-5
Router(config-ips-auto-update)# $s-auto-update/IOS_reqSeq-dw.xml
Router(config-ips-auto-update)#^Z
Router#*May 4 2006 15:50:28 MST: IPS Auto Update: setting update timer for next update: 0 hrs 10 min*May 4 2006 15:50:28 MST: %SYS-5-CONFIG_I: Configured from console by cisco on consoleRouter#Router# show ip ips auto-update
IPS Auto Update ConfigurationURL : tftp://192.168.0.2/jdoe/ips-auto-update/IOS_reqSeq-dw.xmlUsername : not configuredPassword : not configuredAuto Update Intervalsminutes (0-59) : 0hours (0-23) : 0-23days of month (1-31) : 1-31days of week: (0-6) : 1-5Related Commands
signature
To specify a signature for which the command-line interface (CLI) user tunings will be changed, use the signature command in signature-definition-signature (config-sigdef-sig) configuration mode. To remove the CLI user tunings and revert to the default values, use the no version of this command.
signature signature-id [subsignature-id]
no signature signature-id [subsignature-id]
Syntax Description
Command Default
Default signature parameters cannot be changed.
Command Modes
Signature-definition-signature configuration (config-sigdef-sig)
Command History
Usage Guidelines
Use the signature command to specify a signature whose CLI user tunings are to be customized. Thereafter, you can begin to specify which signature parameters (user tunings) are to be changed.
Examples
The following example shows how to modify signature 5081/0 to "produce alert" and "reset tcp connection":
Router(config)# ip ips signature-definition
Router(config-sigdef-sig)# signature 5081 0
Router(config-sigdef-action)# engine
Router(config-sigdef-action-engine)# event-action produce-alert reset-tcp-connection
Router(config-sigdef-action-engine)# ^Z
Do you want to accept these changes:[confirmm]y
Related Commands
Command Descriptionip ips signature-definition
Enters signature-definition-signature configuration mode, which allows you to define a signature for CLI user tunings.
status
To enter the signature-definition-status configuration mode, which allows you to change the enabled or retired status of an individual signature, use the status command in signature-definition-action configuration mode. To return to the default action, use the no form of this command.
status
Syntax Description
This command has no arguments or keywords.
Command Default
None
Command Modes
Signature-definition-action configuration (config-sigdef-action)
Command History
Usage Guidelines
Before issuing the status command, you must specify at least one signature via the signature command.
Examples
The following example shows how to change the status of signature 9000:0 to enabled:
Router(config)# ip ips signature-definition
Router(config-sigdef-sig)# signature 9000 0
Router(config-sigdef-action)# status
Router(config-sigdef-status)# enabled true
Related Commands
target-value
To define the target value rating for a host, use the target-value command in configuration rule configuration mode. To change the target value rating or revert to the default value, use the no form of this command.
target-value {mission-critical | high | medium | low} target-address ip-address [/nn | to ip-address]
no target-value {mission-critical | high | medium | low} target-address ip-address [/nn | to ip-address]
Syntax Description
Command Default
medium
Command Modes
Configuration rule configuration (config-rul)
Command History
Usage Guidelines
Use the target-value command to set the target value rating, which allows users to develop security policies that can be more strict for some resources than others. The security policy is applied to a table of hosts that are protected by Cisco IOS Intrusion Prevention System (IPS). A host can be a single IP address or a range of IP addresses with an associated target value rating.
Note
Changes to the target value rating is not shown in the run time config because the changes are recorded in the seap-delta.xml file, which can be located via the ip ips config location command.
Examples
The following example shows how to change the target value to low for the host 192.168.0.1:
configure terminalip ips event-action-rulestarget-value low target-address 192.168.0.1url (ips-auto-update)
To define a location in which to retrieve the Cisco IOS Intrusion Prevention System (IPS) signature configuration files, use the url command in IPS-auto-update configuration mode.
url url
Syntax Description
Command Default
The default value is defined in the signature definition XML.
Command Modes
IPS-auto-update configuration
Command History
Usage Guidelines
Automatic signature updates allow users to override the existing IPS configuration and automatically keep signatures up to date on the basis of a preset time, which can be configured to a preferred setting.
Examples
In this example, the signature package file is pulled from the TFTP server at the start of every hour or every day, Sunday through Thursday. (Note that adjustments are made for months without 31 days and daylight savings time.)
Router# show ip ips auto-update
IPS Auto Update ConfigurationURL : tftp://192.168.0.2/jdoe/ips-auto-update/IOS_reqSeq-dw.xmlUsername : not configuredPassword : not configuredAuto Update Intervalsminutes (0-59) : 0hours (0-23) : 0-23days of month (1-31) : 1-31days of week: (0-6) : 1-5Related Commands
username (ips-autoupdate)
To define a username and password in which to access signature files from the server, use the username command in IPS-auto-update configuration mode.
username name password password
Syntax Description
name
Username required to access the latest updated signature file package.
password password
Password required to access the latest updated signature file package.
Command Default
The default value is defined in the signature definition XML.
Command Modes
IPS-auto-update configuration
Command History
Usage Guidelines
Automatic signature updates allow users to override the existing Intrusion Prevention System (IPS) configuration and automatically keep signatures up to date on the basis of a preset time, which can be configured to a preferred setting.
Use the ip ips auto-update command to enable Cisco IOS IPS to automatically update the signature file on the system. Thereafter, you can optionally issue the username command to specify a username and password to access signature files.
Examples
The following example shows how to configure automatic signature updates and issue the show ip ips auto-update command to verify the configuration:
Router# clock set ?
hh:mm:ss Current TimeRouter# clock set 10:38:00 20 apr 2006
Router#*Apr 20 17:38:00.000: %SYS-6-CLOCKUPDATE: System clock has been updated from 10:37:55 MST Thu Apr 20 2006 to 10:38:00 MST Thu Apr 20 2006, configured from console by cisco on console.Router(config)# ip ips auto-update
Router(config-ips-auto-update)# occur-at 0 0-23 1-31 1-5
Router(config-ips-auto-update)# $s-auto-update/IOS_reqSeq-dw.xml
Router(config-ips-auto-update)#^Z
Router#*May 4 2006 15:50:28 MST: IPS Auto Update: setting update timer for next update: 0 hrs 10 min*May 4 2006 15:50:28 MST: %SYS-5-CONFIG_I: Configured from console by cisco on consoleRouter#Router# show ip ips auto-update
IPS Auto Update ConfigurationURL : tftp://192.168.0.2/jdoe/ips-auto-update/IOS_reqSeq-dw.xmlUsername : not configuredPassword : not configuredAuto Update Intervalsminutes (0-59) : 0hours (0-23) : 0-23days of month (1-31) : 1-31days of week: (0-6) : 1-5Related Commands
Feature Information for Cisco IOS 5.x Format Signatures with Cisco IOS IPS
Table 1 lists the release history for this feature.
Not all commands may be available in your Cisco IOS software release. For release information about a specific command, see the command reference documentation.
Use Cisco Feature Navigator to find information about platform support and software image support. Cisco Feature Navigator enables you to determine which Cisco IOS and Catalyst OS software images support a specific software release, feature set, or platform. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.
Note
Table 1 lists only the Cisco IOS software release that introduced support for a given feature in a given Cisco IOS software release train. Unless noted otherwise, subsequent releases of that Cisco IOS software release train also support that feature.
Any Internet Protocol (IP) addresses used in this document are not intended to be actual addresses. Any examples, command display output, and figures included in the document are shown for illustrative purposes only. Any use of actual IP addresses in illustrative content is unintentional and coincidental.
© 2006 Cisco Systems, Inc. All rights reserved.