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IDP Utility for Packet Capture

The IDP utility for packet capture is a specialized tool on SRX Series Firewalls that captures, manages, and allows analysis of packet data related to IDP events.

The packet capture utility is used to analyze packet capture files that record network traffic. The IDP Utility allows network administrators to examine these packet capture files to identify potential security threats or anomalies within network traffic.

Use Feature Explorer to confirm platform and release support for specific features.

Review the Platform-Specific Packet Capture Behavior section for notes related to your platform.

Packet Capture

Packet capture in IDP on Juniper Networks SRX Series Firewalls is a feature that captures and analyzes network traffic to detect and prevent security threats.

The CLI support is provided to display and clear contexts and the associated data only for the packet capture traffic, which improves the IDP validation process.

You can run the packet capture utility in either inet mode or transparent mode to generate protocol contexts. You should run the command line packet capture feeder utility tool from the UNIX shell prompt (%).

A packet capture feeder utility uses a pair of source and destination IPv4 addresses available in the traffic interfaces where the packets are to be fed. The packet capture feeder utility also uses the IPV4 addresses configured for the interfaces through which these PCAPs are injected. Once the PCAPs are fed to these interfaces, a list of contexts associated with the PCAPs and the data are matched for the context. The context, hits, and associated data will be displayed only for traffic that is generated by the packet capture feeder. Live traffic statistics will not be captured. While feeding packets, make sure to feed the packets to the subnet IP of the interface. If you feed packets to the interface IP, IDP security processing might not detect the contexts. You can use all other subnet IP addresses, except for the interface IP.

Before you run new PCAPs through packet capture feeder utility tool, clear the existing contexts and data by using the following clear contexts commands:

Sample command used for Inet mode packet capture feeder:

Or

Sample command used for transparent mode packet capture feeder:

Or

Table 1 defines the PCAP feeder tool fields from the above provided sample outputs.

Table 1:

Fields

Description

pcap --quiet

Suppresses logs from appearing in the console

pcap --verbose

Enables logs to appear in the console

interface-ip1

IP address of the first interface for feeding packet capture packets

interface-ip2

IP address of the other interface for feeding packet capture packets

pcap-ip1

IP address seen in the packet capture

pcap-ip2

Another IP address seen in the packet capture

interface1

Interface 1 in SRX Series Firewall

interface2

Interface 1 in SRX Series Firewall

Packet capture feeder does not support:

  • IPv6

  • Multiple channel protocols such as FTP

Example: Configure Packet Capture Feeder

This example explains how to run the packet capture (PCAP) feeder in inet mode to generate protocol contexts.

Requirements

Before you begin:

  • Configure network interfaces.

Overview

To run the PCAP feeder with a relevant IDP policy to get the associated protocol contexts. In this example, PCAPs are fed using pcap-ip1 6.0.0.1 and pcap-ip2 7.0.0.1 in quiet mode.

Configuration

Procedure

CLI Quick Configuration

To quickly configure this example, copy the following commands, paste them into a text file, remove any line breaks, change any details necessary to match your network configuration, and then copy and paste the commands into the CLI at the [edit] hierarchy level, and then enter commit from configuration mode.

Step-by-Step Procedure

The following example requires you to navigate various levels in the configuration hierarchy. For instructions on how to do that, see Using the CLI Editor in Configuration Mode in the CLI User Guide.

To create an application and associate it with an IDP policy:

  1. Create a policy by assigning a meaningful name to it, associate a rulebase with the policy , add rules to the rulebase, and define match criteria for the rule.

  2. Configure policies.

  3. Configure zones and assign interfaces.

  4. Configure forwarding interfaces.

Results

From configuration mode, confirm your configuration by entering the show security idp and show applications commands. If the output does not display the intended configuration, repeat the configuration instructions in this example to correct it.

If you are done configuring the device, enter commit from configuration mode.

Verification

To confirm that the configuration is working properly, perform this task:

Verify the Configuration

Purpose

Verify the IDP attack context after you run the PCAPs using the PCAP feeder tool.

Action

From operational mode, enter the show security idp attack context command.

Sample Output

Example: Configure Packet Capture Feeder in Transparent Mode

This example explains how to run the packet capture (PCAP) feeder in transparent mode to generate protocol contexts.

Requirements

Before you begin:

  • Configure network interfaces.

Overview

To run a PCAP feeder with a relevant IDP policy to get the associated protocol contexts out of the packets which are running from the packet capture. In this example, PCAP feeder pcap-ip 2 7.0.0.1 is used in quiet mode to feed the packets.

Configuration

Procedure

CLI Quick Configuration

To quickly configure this example, copy the following commands, paste them into a text file, remove any line breaks, change any details necessary to match your network configuration, and then copy and paste the commands into the CLI at the [edit] hierarchy level, and then enter commit from configuration mode.

Step-by-Step Procedure

The following example requires you to navigate various levels in the configuration hierarchy. For instructions on how to do that, see Using the CLI Editor in Configuration Mode in the CLI User Guide.

To create an application and associate it with an IDP policy:

  1. Set the configuration group.

  2. Create a policy by assigning a meaningful name to it, associate a rulebase with the policy , add rules to the rulebase, and define match criteria for the rule.

  3. Configure policies.

  4. Configure zones and assign interfaces.

  5. Configure forwarding interfaces.

  6. Configure VLAN-ID.

Results

From configuration mode, confirm your configuration by entering the show security idp and show applications commands. If the output does not display the intended configuration, repeat the configuration instructions in this example to correct it.

If you are done configuring the device, enter commit from configuration mode.

Verification

To confirm that the configuration is working properly, perform this task:

Verify the Configuration

Purpose

Verify the IDP attack context after you run the PCAPs using the PCAP feeder tool.

Action

From operational mode, enter the show security idp attack context command.

Sample Output

Platform-Specific Packet Capture Behavior

Use Feature Explorer to confirm platform and release support for specific features.

Use the following table to review platform-specific behaviors for your platform.

Platform

Difference

SRX Series Firewalls

SRX300, SRX320, SRX340, and SRX345 Firewalls that support Packet Capture support the request security idp pcap-analysis command that allows users to view the current analysis state and reset previously processed data specifically for packet capture traffic.