Security Configuration Guide: Cisco IOS Intrusion Prevention System, Cisco IOS Release 12.4T
Cisco IOS IPS 5.x Signature Format Support and Usability Enhancements
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Cisco IOS IPS 5.x Signature Format Support and Usability Enhancements

Contents

Cisco IOS IPS 5.x Signature Format Support and Usability Enhancements

Last Updated: August 14, 2012

The Cisco IOS Intrusion Prevention System (IPS) acts as an in-line intrusion prevention sensor that scans packets and sessions as they flow through the router to match any Cisco IOS IPS 5.x signature. These signatures are defined in Extensible Markup Language (XML) format and provide the following functionality:

  • 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.
  • Top-level signature categories to classify signatures for easy grouping and tuning. Group-wide parameters, such as signature event action, can be applied to a group through CLI, so the user does not have to modify each individual signature.
  • Encrypted (NDA) signature support.
  • Direct Download from CCO capability in IOS IPS feature allows an administrator to use the CLI to specify, download and upgrade to new signatures posted for the IOS directly from Cisco.com. An administrator can also configure the router through the CLI to receive future periodic signature downloads automatically to eliminate the manual maintenance efforts and costs of changing or tuning IPS signatures whenever a new update is posted.

Finding Feature Information

Your software release may not support all the features documented in this module. For the latest caveats and feature information, see Bug Search Tool and the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the feature information table at the end of this module.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.

Prerequisites for Cisco IOS IPS 5.x Signature Format Support and Usability Enhancements

System and Image Requirements for Cisco IOS IPS 5.x

  • Cisco IOS IPS signatures. See the "Cisco IOS Signature Package" section for more information.
  • 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 rsa
named-key realm-cisco.pub signature
key-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 (realm-cisco.pub.key.txt) configuration at the following URL: http://www.cisco.com/cgi-bin/tablebuild.pl/ios-v5sigup. Ensure that you have your Cisco userid, and password to access this URL.
  • 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 through the ip ips name ips-name command)
  • Interfaces for which the Cisco IOS IPS rule has been applied

To gather this information, issue the show ip ips configurationcommand, which displays a copy of the existing output.

Router# show ip ips configuration
 
Configured SDF Locations:
disk2:my-signatures.sdf
Builtin signatures are enabled but not loaded
Last successful SDF load time: 05:31:54 MST Sep 20 2003
IPS fail closed is disabled
Fastpath ips is enabled
Quick run mode is enabled
Event notification through syslog is enabled
Event notification through SDEE is enabled
Total Active Signatures: 13
Total Inactive Signatures: 0
Signature 50000:0 disable
Signature 50000:1 disable
Signature 50000:2 disable
IPS Rule Configuration
IPS name MYIPS
Interface Configuration
Interface GigabitEthernet0/1
Inbound IPS rule is MYIPS
Outgoing IPS rule is not set

Direct Download from CCO capability in IOS IPS Support

The router must have access to Cisco.com in order for IPS signatures to be upgraded directly from Cisco.com. If the router does not have access to Cisco.com, then signature file updates can still be able to be retrieved from a local server.

Restrictions for Cisco IOS IPS 5.x Signature Format Support and Usability Enhancements

DANGER

Do not enable all IPS signatures at once. The router may not be able to compile all of the signatures, resulting in high CPU and memory usage, degraded performance, or a system reload.

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 is 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 IPS 5.x Signature Format Support and Usability Enhancements

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 through 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.

Cisco IOS IPS Signature Scanning with Lightweight Signatures

The addition of Cisco IOS IPS signature scanning with lightweight signatures in Cisco IOS Release 15.0(1)M is an enhancement to Cisco IOS IPS that allows loading of larger signatures sets, without consuming significant additional memory or reducing the memory consumed by an existing signature set, by loading equivalent lighter-weight signatures. These signatures are referred to as lightweight signatures.

For the signatures made obsolete by new lightweight signatures from new signature scanning engines, Cisco IOS provides the ip ips inherit-obsolete-tunings command to apply common parameters the user may have changed (customized) in the old signature file (delta.xml), to the equivalent new signature file. For more information, see "Enabling Signature Tunings Inheritance".

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 through a directory that contains three configuration files--the default configuration, the delta configuration, and the SEAP configuration. Cisco IOS accesses this directory through 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, are now stored in the delta configuration file; thus, support for access control lists (ACLs) is no longer necessary.

Additional Risk Rating Algorithms

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:

Cisco IOS IPS Signature Package

The latest Cisco IOS IPS signature package can be accessed from Cisco.com using the following URL: http://www.cisco.com/cisco/software/release.html?mdfid=281442967&release=S636&relind=AVAILABLE&flowid=4836&softwareid=280775022&rellifecycle=&reltype=latest

Note


Ensure that you have your Cisco userid, and password to access this URL.
  • The IOS-Sxxx-CLI.pkg file is listed on this web page. See the "Configuring Cisco IOS IPS on Your Router" for more information on creating a directory on the router flash directory where the required signature files and configurations are stored. Alternatively, you can use a Cisco USB flash drive connected to the router's USB port to store the signature files and configurations. The USB flash drive needs to remain connected to the router USB port if it is used as the IOS IPS configuration directory location. IOS IPS also supports any IOS File System as its configuration location with proper write access.

Preserving Configured Signature Tunings on the Local Router

Most IPS devices and applications provide either a single default configuration or multiple default configurations. Using one of these default configurations is an ideal starting point for deploying IPS. When IOS IPS is deployed, parameters such as severity, active status or event actions of certain signatures need to be tuned to meet the requirements of an enterprise network traffic profile.

Once the ip ips enable-clidelta command is enabled, a local cli-delta.xmz file is generated containing the local tuning signatures configured through the CLI. The settings in the clidelta.xmz file take precedence when a globally administered delta signature update, contained in the iosips-sig-delta.xmz file, is sent from a central repository and applied to the configuration of the local router. See "Tuning Signatures per Signature ID" for more information about the configuration of this feature.

How to Use Cisco IOS IPS 5.x Signature Format Support and Usability Enhancements

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 does not build the parallel scanning data structure.

Retired signatures are not scanned by Cisco IOS IPS, so they do 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 [subcategory]

5.    retired {true | false}

6.    exit

7.   category category [subcategory]

8.    retired {true | false}

9.    exit


DETAILED STEPS
  Command or Action Purpose
Step 1
enable


Example:

Router> enable

 

Enables privileged EXEC mode.

  • Enter your password if prompted.
 
Step 2
configure terminal


Example:

Router# configure terminal

 

Enters global configuration mode.

 
Step 3
ip ips signature-category


Example:

Router(config)# ip ips signature-category

 

Enters enters IPS category configuration mode.

 
Step 4
category category [subcategory]


Example:

Router(config-ips-category)# category all

 

Specifies that all categories (and all signatures) are retired in the following step and enters IPS category action configuration mode.

 
Step 5
retired {true | false}


Example:

Router(config-ips-category-action)# retired true

 

Specifies that the router should retire all categories (and all signatures).

  • true --Retires all signatures within a given category.
  • false --"Unretires" all signatures within a given category.
 
Step 6
exit


Example:

Router(config-ips-category-action)# exit

 

Exits IPS category action configuration mode.

 
Step 7
category category [subcategory]


Example:

Router(config-ips-category)# category ios_ips basic

 

Specifies the basic category (and a set of signatures) that are to be "unretired" in the following step.

 
Step 8
retired {true | false}


Example:

Router(config-ips-category-action)# retired false

 

Specifies that all signatures within the basic category are to be unretired; that is, signatures are enabled for the basic category.

 
Step 9
exit


Example:

Router(config-ips-category-action)# exit

 

Exits IPS category action and IPS category configuration modes.

 

What to Do Next

After you have configured the basic category, you should enable IPS on your router. See "Configuring Cisco IOS IPS on Your Router" for more information.

You can customize (or tune) either the entire category or individual signatures within a category to addresses the needs of your network. See "Tuning Signature Parameters", for more information.

Configuring Cisco IOS IPS on Your Router

After you have set up a "load definition" for the signatures 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
  Command or Action Purpose
Step 1
enable


Example:

Router> enable

 

Enables privileged EXEC mode.

  • Enter your password if prompted.
 
Step 2
mkdir flash:/ips5


Example:

Router# mkdir flash:/ips5

 

Create a directory for which Cisco IOS IPS saves signature information.

Note    The directory location is specified through the ip ips config location command.
 
Step 3
configure terminal


Example:

Router# configure terminal

 

Enters global configuration mode.

 
Step 4
ip ips name ips-name


Example:

Router(config)# ip ips name myips

 

Creates an IPS rule.

 
Step 5
ip ips config location url


Example:

Router(config)# ip ips config location flash:/ips5

 

Specifies the location where Cisco IOS IPS saves the signature information, and, if necessary, access the signature configuration information.

Note    You must specify a location; otherwise, the signatures are not saved.
Note    If the specified location is a URL, such as an FTP server, the user must have writer privileges.
 
Step 6
interface type name


Example:

Router(config)# interface gigbitEthernet 0/0

 

Identifies the interface in which to enable Cisco IOS IPS and enters interface configuration mode.

 
Step 7
ip ips ips-name {in | out}


Example:

Router(config-if)# ip ips MYIPS in

 

Applies an IPS rule at an interface and automatically loads the signatures and builds the signature engines.

Note    Whenever signatures are replaced or merged, the router prompt is suspended while the signature engines for the newly added or merged signatures are being built. The router prompt is available again after the engines are built. Depending on your platform and how many signatures are being loaded, building the engine can take up to several minutes. It is recommended that you enable logging messages to monitor the engine building status.
 
Step 8
exit


Example:

Router(config-if)# exit



Example:

Router(config)# exit

 

Exits interface and global configuration modes.

 
Step 9
show ip ips configuration


Example:

Router# show ip ips configuration

 

(Optional) Verifies that Cisco IOS IPS is properly configured.

 
Step 10
show ip ips signature count


Example:

Router# show ip ips signature

 

(Optional) Verifies the number of signatures that are loaded into each signature micro engine (SME).

 

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 S247.0
Trend SDF release version V1.2
Signature Micro-Engine: multi-string
Total Signatures: 7
Enabled: 7 
Retired: 2 
Compiled: 5 
Signature Micro-Engine: service-http
Total Signatures: 541
Enabled: 284 
Retired: 336 
Compiled: 205 
Signature Micro-Engine: string-tcp
Total Signatures: 487
Enabled: 332 
Retired: 352 
Compiled: 135 
Signature Micro-Engine: string-udp
Total Signatures: 50
Enabled: 3 
Retired: 23 
Compiled: 27 
Signature Micro-Engine: state
Total Signatures: 26
Enabled: 15 
Retired: 23 
Compiled: 3 
Signature Micro-Engine: atomic-ip
Total Signatures: 140
Enabled: 87 
Retired: 93 
Compiled: 46 
Inactive - invalid params: 1 
Signature Micro-Engine: string-icmp
Total Signatures: 2
Enabled: 0 
Retired: 1 
Compiled: 1 
Signature Micro-Engine: service-ftp
Total Signatures: 3
Enabled: 3 
Compiled: 3 
Signature Micro-Engine: service-rpc (INACTIVE)
Signature Micro-Engine: service-dns
Total Signatures: 1
Enabled: 1 
Retired: 1 
Signature Micro-Engine: normalizer
Total Signatures: 9
Enabled: 9 
Compiled: 9 
Total Signatures: 1266
Total Enabled Signatures: 741
Total Retired Signatures: 831
Total Compiled Signatures: 434
Total Signatures with invalid parameters: 1

Loading a Signature File into Cisco IOS IPS

Use this task to load signatures into Cisco IOS IPS. You may wish to load new signatures into Cisco IOS IPS if a signature (or signatures) with the current signatures are not providing your network with adequate protection from security threats.

Prerequisites

You must enable Cisco IOS IPS. See "Configuring Cisco IOS IPS on Your Router" before loading new signatures.

Flexible Signatures Ordered and Incremental

Each signature is compiled 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.    end

7.    copy url idconf


DETAILED STEPS
  Command or Action Purpose
Step 1
enable


Example:

Router> enable

 

Enables privileged EXEC mode.

  • Enter your password if prompted.
 
Step 2
configure terminal


Example:

Router# configure terminal

 

Enters global configuration mode.

 
Step 3
ip ips config location url


Example:

Router(config)# ip ips config location flash:/ips5

 

Specifies the location where Cisco IOS IPS saves the signature information, and, if necessary, access the signature configuration information.

 
Step 4
interface type name


Example:

Router(config)# interface gigbitEthernet 0/0

 

Identifies the interface in which to enable Cisco IOS IPS.

 
Step 5
ip ips ips-name {in | out}


Example:

Router(config-if)# ip ips MYIPS in

 

Applies an IPS rule at an interface and automatically loads the signatures and builds the signature engines.

 
Step 6
end


Example:

Router(config-if)# end

 

Exits interface configuration mode.

 
Step 7
copy url idconf


Example:

Router# copy tftp://tftp_server/sig.xml idconf

 

Loads signatures into Cisco IOS IPS.

After the signatures are loaded, all signature information is saved to the location specified through the ip ips config location command.

 

Enabling IPS Regex Table Chaining

Regex Table Chaining is an enhancement to Cisco IOS IPS in Cisco IOS Release 15.0(1)M, that allows the IPS to chain multiple regular (regex) tables together when signatures are being loaded. This functionality is enabled by the ip ips memory regex chaining command. Enabling regex table chaining allows three regex tables to be chained. There is a slight performance degradation in IPS scanning time due to the scanning of multiple tables.

When a user tries to load a specific set of signatures that does not fit using a single table, compilation errors result.

SUMMARY STEPS

1.    enable

2.    configure terminal

3.    ip ips memory regex chaining


DETAILED STEPS
  Command or Action Purpose
Step 1
enable


Example:

Router> enable

 

Enables privileged EXEC mode.

  • Enter your password if prompted.
 
Step 2
configure terminal


Example:

Router# configure terminal

 

Enters global configuration mode.

 
Step 3
ip ips memory regex chaining


Example:

Router(config)# ip ips memory regex chaining

 

Enables IPS regex table chaining when signatures are being loaded.

 

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:


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 through the ip ips config locationcommand.

Tuning Signatures for a 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 enable-clidelta

4.    ip ips signature-definition

5.    signature signature-id [signature-id]

6.    engine

7.    event-action action

8.    exit

9.    alert-severity {high | medium | low | informational}

10.    fidelity-rating rating

11.    status

12.    enabled {true | false }

13.    exit

14.    show ip ips signature

15.    show ip ips sig-clidelta


DETAILED STEPS
  Command or Action Purpose
Step 1
enable


Example:

Router> enable

 

Enables privileged EXEC mode.

  • Enter your password if prompted.
 
Step 2
configure terminal


Example:

Router# configure terminal

 

Enters global configuration mode.

 
Step 3
ip ips enable-clidelta


Example:

Router(config)# ip ips enable-clidelta

 

(Optional) Enables the signature tuning settings in the clidelta.xmz file on the router to take precedence over the signature settings in the IPS iosips-sig-delta.xmz file.

 
Step 4
ip ips signature-definition


Example:

Router(config)# ip ips signature-definition

 

Enters signature-definition-signature configuration mode.

 
Step 5
signature signature-id [signature-id]


Example:

Router(config-sigdef-sig)# signature 9000:0

 

Specifies a signature for which the CLI user tunings are changed and enters signature-definition-action configuration mode.

 
Step 6
engine


Example:

Router(config-sigdef-action)# engine

 

(Optional) Enters signature-definition-action-engine configuration mode, which allows you to change router actions for a specified signature.

 
Step 7
event-action action


Example:

Router(config-sigdef-action-engine)# event-action deny-attacker-inline

 

Changes router actions for a specified signature.

The action argument can be any of the following options:

  • deny-attacker-inline
  • deny-connection-inline
  • deny-packet-inline
  • produce-alert
  • reset-tcp-connection
Note    Signature event actions must be entered on a single line.
Note    You must enter the engine command before issuing this command.
 
Step 8
exit


Example:

Router(config-sigdef-action-engine)# exit

 

Exits the signature-definition-action-engine configuration mode.

This step is required only if the engine and event-action commands are issued.

 
Step 9
alert-severity {high | medium | low | informational}


Example:

Router(config-sigdef-action)# alert-severity medium

 

(Optional) Changes the alert severity rating for a given signature.

 
Step 10
fidelity-rating rating


Example:

Router(config-sigdef-action)# fidelity-rating 2

 

(Optional) Changes the signature fidelity rating for a given signature.

 
Step 11
status


Example:

Router(config-sidef-action)# status

 

(Optional) Enters the signature-definition-status configuration mode, which allows you to change the enabled status of a signature.

 
Step 12
enabled {true | false }


Example:

Router(config-sigdef-status)# enabled true

 

(Optional) Changes the enabled status of a given signature or signature category.

 
Step 13
exit


Example:

Router(config-sigdef-status)# exit

 

Returns to EXEC mode.

 
Step 14
show ip ips signature


Example:

Router# show ip ips signature

 

(Optional) Verifies the signature changes that have been made.

 
Step 15
show ip ips sig-clidelta


Example:

Router# show ip ips sig-clidelta

 

(Optional) Displays the signature parameter tunings configured using the CLI, which are stored in the iosips-sig-clidelta.xmz signature file.

 

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. See "Retiring All Signatures and Selecting a Category of Signatures" before all other category tuning. If a category is configured more than once, the parameters entered in the second configuration are added to or replace the previous configuration.
SUMMARY STEPS

1.    enable

2.    configure terminal

3.    ip ips signature-category

4.    category category [subcategory]

5.    event-action action

6.   alert-severity {high | medium | low | informational}

7.    fidelity-rating rating

8.    enabled {true | false}

9.    retired {true | false }

10.    end

11.    show ip ips signature


DETAILED STEPS
  Command or Action Purpose
Step 1
enable


Example:

Router> enable

 

Enables privileged EXEC mode.

  • Enter your password if prompted.
 
Step 2
configure terminal


Example:

Router# configure terminal

 

Enters global configuration mode.

 
Step 3
ip ips signature-category


Example:

Router(config)# ip ips signature-category

 

Enters IPS category configuration mode.

 
Step 4
category category [subcategory]


Example:

Router(config-ips-category)# category attack adware/spyware

 

Specifies a category that is to be used for multiple signature actions or conditions and enters IPS category action configuration mode.

 
Step 5
event-action action


Example:

Router(config-ips-category-action)# event-action produce-alert

 

Changes router actions for a specified signature category.

Theaction argument can be any of the following options:

  • deny-attacker-inline
  • deny-connection-inline
  • deny-packet-inline
  • produce-alert
  • reset-tcp-connection
Note    Event actions associated with a category can be entered separately or on a single line.
 
Step 6
alert-severity {high | medium | low | informational}


Example:

Router(config-ips-category-action)# alert-severity medium

 

(Optional) Changes the alert severity rating for a given signature category.

 
Step 7
fidelity-rating rating


Example:

Router(config-ips-category-action)# fidelity-rating

 

(Optional) Changes the signature fidelity rating for a signature given category.

 
Step 8
enabled {true | false}


Example:

Router(config-ips-category-action)# enabled true

 

(Optional) Changes the enabled status of a given signature or signature category.

 
Step 9
retired {true | false }


Example:

Router(config-ips-category-action)# retired true

 

(Optional) Specifies whether or not the router should retire a signature category.

 
Step 10
end


Example:

Router(config-ips-category-action)# end



Example:  

Returns to EXEC mode.

 
Step 11
show ip ips signature


Example:

Router# show ip ips signature

 

(Optional) Verifies the signature category changes that have been made.

 

Enabling Signature Tunings Inheritance

When new signatures are replacing older signatures, Cisco IOS IPS provides the ip ips inherit-obsolete-tunings command to enable new signatures to obsolete older signatures and inherit the event-action and enabled parameters of the obsolete tuning values, without the need to manually tune the new signatures. This functionality is called signature tuning inheritance. All other parameter changes including the "Retire" parameter is ignored.

After you enter the command, the screen displays a warning message asking you to clarify the intended usage and then asks whether you accept the configuration or not. By default, old signatures are not inherited by new signatures.

SUMMARY STEPS

1.    enable

2.    configure terminal

3.    ip ips inherit-obsolete-tunings


DETAILED STEPS
  Command or Action Purpose
Step 1
enable


Example:

Router> enable

 

Enables privileged EXEC mode.

  • Enter your password if prompted.
 
Step 2
configure terminal


Example:

Router# configure terminal

 

Enters global configuration mode.

 
Step 3
ip ips inherit-obsolete-tunings

Example:

Router(config)#ip ips inherit-obsolete-tunings

 

Enables the inheritance of the tunings of the enabled and event-action parameters from obsolete signatures to new signatures in an IPS,

 

Setting an IPS Memory Threshold

When a router is powered up, 90 percent of the available memory is allocated to IPS-related activities. The remaining 10 percent is referred to as the IPS Memory Threshold--the amount of free memory unavailable to the IPS. Cisco IOS IPS allows the IPS memory threshold to be set to a different value using the ip ips memory threshold command.

SUMMARY STEPS

1.    enable

2.    configure terminal

3.    ip ips memory threshold megabytes


DETAILED STEPS
  Command or Action Purpose
Step 1
enable


Example:

Router> enable

 

Enables privileged EXEC mode.

  • Enter your password if prompted.
 
Step 2
configure terminal


Example:

Router# configure terminal

 

Enters global configuration mode.

 
Step 3
ip ips memory threshold megabytes


Example:



Example:



Example:



Example:

Router(config)# ip ips memory threshold 50

 

Specifies an IPS memory threshold, or the amount of free memory unavailable to the IPS.

  • The units are in megabytes (MB).
  • This example specifies that Cisco IOS IPS cannot consume more memory if the remaining (free) memory becomes less than 50 MB.
 

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 through 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
  Command or Action Purpose
Step 1
enable


Example:

Router> enable

 

Enables privileged EXEC mode.

  • Enter your password if prompted.
 
Step 2
configure terminal


Example:

Router# configure terminal

 

Enters global configuration mode.

 
Step 3
ip ips event-action-rules


Example:

Router(config)# ip ips event-action-rules

 

Enters the config-rule configuration mode, which allows users to change the target value rating.

 
Step 4
target-value {mission-critical | high | medium | low} target-address ip-address [/nn | to ip-address]


Example:

Router(config-rul)# target-value medium target-address 10.12.100.53

 

Sets the target value rating for a host to rate how important the system is to the network.

  • The target-address keyword and arguments specify a host, which can consist of a single IP address or range of IP addresses.
 
Step 5
exit


Example:

Router(config-rul)# exit

 

Exits config-rule configuration mode.

 

Configuring Signature Auto Updates from a Local Server


Note


This functionality was introduced through the Cisco IOS IPS 5.x Signature Format and Usability Enhancements feature in Cisco IOS Release 12.4(11)T.
SUMMARY STEPS

1.    enable

2.    configure terminal

3.    key config-key password-encrypt

4.    password encryption aes

5.    ip ips auto-update

6.    occur-at {[monthly | weekly] days minutes hours}

7.    username name password password

8.    url url

9.    exit

10.    show ip ips auto-update


DETAILED STEPS
  Command or Action Purpose
Step 1
enable


Example:

Router> enable

 

Enables privileged EXEC mode.

  • Enter your password if prompted.
 
Step 2
configure terminal


Example:

Router# configure terminal

 

Enters global configuration mode.

 
Step 3
key config-key password-encrypt


Example:

Router(config-ips-auto-update)# key config-key password-encrypt

 

Stores a type 6 encryption key in private NVRAM.

 
Step 4
password encryption aes


Example:

Router(config-ips-auto-update)# password encryption aes

 
Enables a type 6 encrypted preshared key.
Note    Once the key config-key password-encrypt and password encryption aes commands are configured, they enable the password (symmetric cipher Advanced Encryption Standard (AES) encrypts the keys).
 
Step 5
ip ips auto-update


Example:

Router(config)# ip ips auto-update

 

Enables automatic signature updates for Cisco IOS IPS and enters IPS auto-update configuration mode.

 
Step 6
occur-at {[monthly | weekly] days minutes hours}


Example:

Router(config-ips-auto-update)# occur-at weekly 4 23 23

 

(Optional) Defines a preset time for which the Cisco IOS IPS automatically obtains updated signature information.

 
Step 7
username name password password


Example:

Router(config-ips-auto-update)# username myips password secret

 

(Optional) Defines a username and password for the signature update function.

 
Step 8
url url


Example:

Router(config-ips-auto-update)# url tftp://10.10.10.5/username1/ips-auto-update/

 

URL from the local server on which the router retrieves the Cisco IOS IPS signature configuration files.

 
Step 9
exit


Example:

Router(config-ips-auto-update)# exit Router(config)# exit

 

Exits IPS auto-update and global configuration modes.

 
Step 10
show ip ips auto-update


Example:

Router# show ip ips auto-update

 

Verifies the signature update configuration.

 

Monitoring Cisco IOS IPS Signatures through 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. See the "Troubleshooting and Fault Management" feature module for more information on configuring syslog messages.

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 responds with a fault response message, indicating that notification is not enabled.

Storing SDEE Events in the Buffer

When SDEE notification is enabled (through 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 starts overwriting the earliest stored events. (If overwritten events have not yet been reported, a buffer overflow notice is received.)
  • If a new, smaller buffer is requested, all events that are stored in the previous buffer is lost.
  • If a new, larger buffer is requested, all existing events are saved.
Before You Begin

To use SDEE, the HTTP server must be enabled (through 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
  Command or Action Purpose
Step 1
enable


Example:

Router> enable

 

Enables privileged EXEC mode.

  • Enter your password if prompted.
 
Step 2
configure terminal


Example:

Router# configure terminal

 

Enters global configuration mode.

 
Step 3
ip ips notify sdee


Example:

Router(config)# ip ips notify sdee

 

Enables SDEE event notification on a router.

 
Step 4
ip sdee events events


Example:

Router(config)# ip sdee events 500

 

(Optional) Sets the maximum number of SDEE events that can be stored in the event buffer.

  • Maximum value: 1000 events.
Note    By default, 200 events can be stored in the buffer when SDEE is enabled. When SDEE is disabled, all stored events are lost; a new buffer is allocated when the notifications are reenabled.
 
Step 5
ip sdee subscriptions subscriptions


Example:

Router(config)# ip sdee subscriptions 1

 

(Optional) Sets the maximum number of SDEE subscriptions that can be open simultaneously.

  • Valid value ranges from 1 to 3.
 
Step 6
ip sdee messages messages


Example:

Router(config)# ip sdee messages 500

 

(Optional) Sets the maximum number of SDEE messages that can be stored in the buffer at one time.

 
Step 7
ip sdee alerts alerts


Example:

Router(config)# ip sdee alerts 2000

 

(Optional) Sets the maximum number of SDEE alerts that can be stored in the buffer at one time.

 
Step 8
exit


Example:

Router(config)# exit

 

Exits global configuration mode.

 
Step 9
show ip sdee [alerts | all | errors | events | configuration | status | subscriptions]


Example:

Router# show ip sdee configuration

 

(Optional) Verifies SDEE configuration information and notification functionality.

 

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 for Cisco IOS IPS 5.x Signature Format Support and Usability Enhancements

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:/ips5
Router#
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                 Protocol
GigabitEthernet0/0       10.0.20.120    YES    NVRAM   up                     up 
GigabitEthernet0/1       10.12.100.120  YES    NVRAM   administratively down  down 
NVI0                     unassigned     NO     unset   up                     up 
Router(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 ms
Router(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 console
Router# wr
Building configuration...
[OK]
Router#
Router# show ip ips signature count
Cisco SDF release version S0.0
Signature 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-ip
     Total Signatures: 3
       Enabled: 0 
       Compiled: 3 
Signature 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: 3
     Total Enabled Signatures: 0
     Total Retired Signatures: 0
     Total Compiled Signatures: 3
Router#
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 e
Router# 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 ms
Router#
Router#
Router# show ip ips signature count
Cisco SDF release version S258.0
Signature Micro-Engine: multi-string
     Total Signatures: 3
       Enabled: 3 
       Retired: 3 
Signature Micro-Engine: service-http
     Total Signatures: 611
       Enabled: 159 
       Retired: 428 
       Compiled: 183 
Signature Micro-Engine: string-tcp
     Total Signatures: 864
       Enabled: 414 
       Retired: 753 
       Compiled: 111 
Signature Micro-Engine: string-udp
     Total Signatures: 74
       Enabled: 1 
       Retired: 44 
       Compiled: 30 
Signature Micro-Engine: state
     Total Signatures: 28
       Enabled: 16 
       Retired: 25 
       Compiled: 3 
Signature Micro-Engine: atomic-ip
     Total Signatures: 252
       Enabled: 56 
       Retired: 148 
       Compiled: 103 
       Inactive - invalid params: 1 
Signature Micro-Engine: string-icmp
     Total Signatures: 3
       Enabled: 0 
       Retired: 2 
       Compiled: 1 
Signature Micro-Engine: service-ftp
     Total Signatures: 3
       Enabled: 1 
       Compiled: 3 
Signature Micro-Engine: service-rpc
            Total Signatures: 75
       Enabled: 44 
       Retired: 44 
       Compiled: 31 
Signature Micro-Engine: service-dns
     Total Signatures: 38
       Enabled: 30 
       Retired: 5 
       Compiled: 33 
Signature Micro-Engine: normalizer
     Total Signatures: 9
       Enabled: 8 
       Retired: 5 
       Compiled: 4 
Signature Micro-Engine: service-smb-advanced (INACTIVE)
Signature Micro-Engine: service-msrpc
     Total Signatures: 22
       Enabled: 22 
       Retired: 22

Configuring and Verifying SDEE on your Router Example

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 console 
Router# show ip sdee all
Configured concurrent subscriptions: 1
No currently open subscriptions.
Alert storage: 2000 alerts using 560000 bytes of memory
Message storage: 500 messages using 212000 bytes of memory
SDEE Events
Time Type Description

Router#

Additional References

Technical Assistance

Description

Link

The Cisco Support and Documentation website provides online resources to download documentation, software, and tools. Use these resources to install and configure the software and to troubleshoot and resolve technical issues with Cisco products and technologies. Access to most tools on the Cisco Support and Documentation website requires a Cisco.com user ID and password.

http://www.cisco.com/cisco/web/support/index.html

Feature Information for Cisco IOS IPS 5.x Signature Format Support and Usability Enhancements

The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.

Table 1 Feature Information for Cisco IOS 5.x Signature Format Support and Usability Enhancements

Feature Name

Releases

Feature Information

Cisco IOS IPS 5.x Signature Format and Usability Enhancements

12.4(11)T

This feature introduces support for Cisco IOS Intrusion Prevention System (IPS) version 5.0, which is a version-based signature definition XML format. Cisco IOS IPS 4.x format signatures are replaced by the 5.x format signatures that are used by all other Cisco IPS devices.

The following commands were introduced or modified by this feature: alert-severity, category, copy idconf enabled (IPS), engine (IPS), event-action, fidelity-rating, ip ips auto-update, ip ips config location, ip ips event-action-rules, ip ips signature-category, ip ips signature-definition, occur-at (ips-auto-update), retired (IPS), show ip ips auto-update, signature, status, target-value url (ips-auto-update), username (ips-autoupdate).

Direct Download from CCO capability in IOS IPS

15.1(1)T

The following commands were introduced or modified by this feature: cisco, ida-client server url, ip ips auto-update, ip signature update cisco, occur-at.

Capability to save local delta changes on IOS routers

15.1(2)T

This feature was introduced to generate a local cli-delta.xmz file on the router containing the signature tuning settings configured through the CLI. This local file takes precedence when a globally administered delta signature update, contained in the IPS iosips-sig-delta.xmz file, is sent from a central repository and applied to the configuration of the local router.

The following commands were introduced or modified: ip ips enable-clidelta, show ip ips sig-clidelta.

Cisco IOS IPS with Lightweight Signatures

15.2(1)T and 15.2(2)T

This feature was deprecated in Cisco IOS Release 15.2(1)T and 15.2(2)T.

The following commands were deprecated: ip ips inherit-obsolete tunings, ip ips memory regex chaining, ip ips memory threshold.

Cisco and the Cisco logo are trademarks or registered trademarks of Cisco and/or its affiliates in the U.S. and other countries. To view a list of Cisco trademarks, go to this URL: www.cisco.com/go/trademarks. Third-party trademarks mentioned are the property of their respective owners. The use of the word partner does not imply a partnership relationship between Cisco and any other company. (1110R)

Any Internet Protocol (IP) addresses and phone numbers used in this document are not intended to be actual addresses and phone numbers. Any examples, command display output, network topology diagrams, and other figures included in the document are shown for illustrative purposes only. Any use of actual IP addresses or phone numbers in illustrative content is unintentional and coincidental.

© 2012 Cisco Systems, Inc. All rights reserved.