Chapter 3 Setting Up the Sensor

Configuring SSH

Step 7 Remove an entry. The host is removed from the SSH known hosts list.

sensor(config)# no ssh host-key 10.16.0.0

Step 8 Verify the host was removed. The IP address no longer appears in the list.

sensor(config)# exit

sensor# show ssh host-keys

Adding Authorized RSA1 and RSA2 Keys

Use the ssh authorized-keycommand to define public keys for a client allowed to use RSA1 or RSA2 authentication to log in to the local SSH server. The default is RSA2. You can configure the sensor to fall back to RSA1. To modify an authorized key, you must remove and recreate the entry. Use the no form of the command to remove the entry. Users can only create and remove their own keys.

The following options apply:

•id—Specifies a 1 to 256-character string that uniquely identifies the authorized key. You can use numbers, “_,” and “-,” but spaces and “?” are not accepted.

•rsa-pubkey—Specifies the RSA (SSHv2) key details.

–pubkey—Specifies the Base64 encoded public key.

•rsa1-pubkey—Specifies the RSA1 (SSHv1) key details:

–key-modulus-length—Specifies an ASCCI decimal integer in the range[511, 2048].

–public-exponent—Specifies an ASCII decimal integer in the range [3, 2^32].

–public-modulus—Specifies an ASCII decimal integer, x, such that (2^(key-modulus-length-1)) < x < (2^(key-modulus-length)).

Each user who can log in to the sensor has a list of authorized public keys. An SSH client with access to any of the corresponding RSA private keys can log in to the sensor as the user without entering a password.

For SSHv1, use an RSA key generation tool on the client where the private key is going to reside. Then, display the generated public key as a set of three numbers (modulus length, public exponent, public modulus) and enter those numbers as parameters for the ssh authorized-key command. For SSHv2, you just need the ID and the public key.

Note You configure your own list of SSH authorized keys. An administrator cannot manage the list of SSH authorized keys for other users on the sensor.

Note An SSH authorized key provides better security than passwords if the private key is adequately safeguarded. The best practice is to create the private key on the same host where it will be used and store it with a pass phrase on a local file system. To minimize password or pass phrase prompts, use a key agent.

 

Cisco Intrusion Prevention System Sensor CLI Configuration Guide for IPS 7.2

3-48

OL-29168-01

Page 115 Page 117
Page 116
Image 116
Cisco Systems IPS4510K9 manual Adding Authorized RSA1 and RSA2 Keys, Sensorconfig# no ssh host-key
Page 115 Page 117

IPS4510K9 specifications

Cisco Systems has long been a leading player in network security, and its IPS (Intrusion Prevention System) series is a testament to its commitment to safeguarding digital environments. Among its notable offerings are the IPS4510K9 and IPS4520K9 models, both designed to provide advanced threat protection for mid-sized to large enterprise networks.

The Cisco IPS4510K9 and IPS4520K9 are distinguished by their cutting-edge features that help organizations defend against a myriad of cyber threats. These systems utilize a multi-layered approach to security, integrating intrusion prevention, advanced malware protection, and comprehensive visibility across the network.

One of the primary characteristics of the IPS4510K9 is its high performance. It boasts a throughput of up to 1 Gbps, making it suitable for environments that demand rapid data processing and real-time responses to threats. The IPS4520K9, on the other hand, enhances that capability with improved throughput of up to 2 Gbps, accommodating larger enterprises with heavier network traffic. These models are equipped with powerful processors that support complex signature matching and can intelligently distinguish between legitimate traffic and potential threats.

In addition to performance, both models are designed with scalability in mind. They can be easily integrated into existing Cisco infrastructures. This facilitates a seamless enhancement of security without causing significant interruptions to ongoing operations. Moreover, they offer flexible deployment options, allowing organizations to operate them inline or out of band depending on their specific needs.

The Cisco IPS4510K9 and IPS4520K9 leverage advanced detection technologies, utilizing a variety of signature types and heuristic analysis to detect known and unknown threats effectively. They are equipped with real-time alerting and reporting capabilities, giving security teams immediate visibility into potential breaches and enabling them to respond swiftly.

Furthermore, both models support a range of management options through the Cisco Security Manager, allowing for centralized administration, streamlined policy management, and enhanced monitoring capabilities. Automated updates ensure the systems remain current with the latest threat intelligence, vital for staying ahead of evolving cyber threats.

In summary, the Cisco Systems IPS4510K9 and IPS4520K9 represent powerful solutions for organizations seeking robust intrusion prevention capabilities. With their high performance, scalability, and advanced detection technologies, these systems are essential tools in the ever-changing landscape of cybersecurity, providing enterprises with the peace of mind needed to operate securely in today's digital world.
Top Page Image Contents