Auditing routers, switches, and firewalls involve evaluating the security and performance of the network infrastructure of an organization.
By conducting an audit of routers, switches, and firewalls, the auditor can provide assurance that the network infrastructure is secure and performing effectively and can help to prevent security breaches and improve the performance of the network.
Auditing operations for routers, switches, and firewalls may include the following:
- Configuration review: Ensure the devices are configured securely and in compliance with policies and best practices.
- Firmware version update: Check and update the firmware version to the latest version for security patches and bug fixes.
- Network topology mapping: Map out the network topology to see how the devices are connected to each other.
- Access control: Verify the access control lists (ACLs) to make sure that unauthorized users cannot access the network.
- Port security: Check the security settings of network interfaces to prevent unauthorized access.
- Log analysis: Review the logs of the devices to identify any security incidents and to monitor network usage.
- Vulnerability scanning: Scan the devices for known vulnerabilities and remediate any found.
- Backup and disaster recovery plan: Ensure the devices have a backup and disaster recovery plan in place.
It is important to regularly audit these devices as they are critical components of the network infrastructure and can be targets for cyber attacks.
Scope:
The scope of auditing routers, switches, and firewalls depends on the specific requirements and objectives of the audit. However, the following are some common areas of focus:
- Network security: Verify that the devices are configured securely to prevent unauthorized access, data breaches, and cyber-attacks.
- Compliance with policies and standards: Ensure that the devices comply with organizational policies and industry standards such as PCI DSS, HIPAA, and NIST.
- Configuration management: Check the configuration of the devices to ensure consistency and avoid configuration errors.
- Performance and availability: Monitor the performance and availability of the devices to ensure they are functioning optimally.
- Vulnerability management: Scan the devices for vulnerabilities and address any identified risks.
- Incident response and management: Evaluate the incident response and management plan to ensure it is effective and efficient in the event of a security breach.
- Change management: Review the change management process to ensure changes are properly controlled and approved.
- Physical security: Ensure the physical security of the devices to prevent theft, damage, and unauthorized access.
Steps to Auditing Routers, Switches, and Firewalls
The steps involved in auditing routers, switches, and firewalls can vary depending on the specific requirements and objectives of the audit, but the following are common steps in the auditing process:
- Preparation: Define the scope, objectives, and requirements of the audit, and gather relevant documentation and tools.
- Network mapping: Map out the network topology to understand the connections between the devices.
- Configuration review: Review the configuration of the devices to ensure they are set up securely and in compliance with policies and standards.
- Log analysis: Review the logs of the devices to identify any security incidents and monitor network usage.
- Vulnerability scanning: Scan the devices for known vulnerabilities and address any identified risks.
- Access control review: Verify the access control settings to ensure unauthorized users cannot access the network.
- Port security review: Check the security settings of network interfaces to prevent unauthorized access.
- Backup and disaster recovery plan review: Evaluate the backup and disaster recovery plan to ensure it is effective and efficient in the event of a failure or security breach.
- Reporting: Compile the results of the audit and present a report that includes recommendations for improvement.
- Remediation: Implement any recommended changes to improve the security and performance of the network infrastructure.
Checklist for Auditing Network Equipment:
- Review controls around developing and maintaining configurations.
- Ensure that appropriate controls are in place for any vulnerabilities associated with the current software version. These controls might include software updates, configuration changes, or other compensating controls.
- Verify that all unnecessary services are disabled.
- Ensure that good SNMP management practices are followed.
- Review and evaluate procedures for creating user accounts and ensuring that accounts are created only when there is a legitimate business need. Also, review and evaluate processes for ensuring that accounts are removed or disabled in a timely fashion in the event of termination or job change.
- Ensure that appropriate password controls are used.
- Verify that secure management protocols are used where possible.
- Ensure that current backups exist for configuration files if applicable.
- Verify that logging is enabled and sent to a centralized system.
- Evaluate the use of the Network Time Protocol (NTP).
- Verify that a banner is configured to make all connecting users aware of the company’s policy for use and monitoring.
- Ensure that access controls are applied to the console port.
- Ensure that all network equipment is stored in a secure location.
- Ensure that a standard naming convention is used for all devices.
- Verify that standard, documented processes exist for building network devices.
Checklist for Auditing Layer 2 Devices: Additional Controls for Switches
- Verify that administrators avoid using VLAN 1.
- Evaluate the use of trunk auto-negotiation.
- Verify that Spanning-Tree Protocol attack mitigation is enabled (BPDU Guard, Root Guard).
- Evaluate the use of VLANs on the network.
- Disable all unused ports, and put them in an unused VLAN.
- Evaluate the use of the VTP in the environment.
- Verify that thresholds exist that limit broadcast/multicast traffic on ports.
Checklist for Auditing Layer 3 Devices: Additional Controls for Routers
- Verify that inactive interfaces on the router are disabled.
- Ensure that the router is configured to save all core dumps.
- Verify that all routing updates are authenticated.
- Verify that IP source routing and IP-directed broadcasts are disabled.
Checklist for Auditing Firewalls: Additional Controls
- Verify that all packets are denied by default.
- Ensure that inappropriate internal and external IP addresses are filtered.
- Evaluate firewall rule sets to provide appropriate protection.
Conclusion
In conclusion, auditing routers, switches, and firewalls is a critical component of ensuring the security and performance of a network infrastructure. The auditing process involves reviewing the configuration, logs, and security settings of these devices to identify vulnerabilities and ensure compliance with policies and standards. Regular auditing helps to prevent security incidents, ensure the devices are functioning optimally, and maintain the integrity of the network infrastructure.
By following the steps of auditing and implementing recommended improvements, organizations can proactively address potential security risks and ensure the security of their network.