Which of the following practices will not help incident responders in containing AWS security incidents?

The practice of implementing a custom route table with interconnection routes within the Virtual Private Cloud (VPC) does not directly help incident responders in containing security incidents. While custom route tables can optimize network traffic and control the flow between subnets, they primarily serve the purpose of routing management and network configuration rather than incident response and containment.

In contrast, regularly updating Identity and Access Management (IAM) policies ensures that only authorized users have access to sensitive resources, which can prevent further compromises during an incident. Isolating impacted resources in a separate VPC is a crucial containment strategy that allows responders to limit the spread of an incident and manage the impacted resources more effectively. Conducting routine security audits helps organizations identify vulnerabilities and risks before they can be exploited, thereby enhancing their overall security posture and readiness for incident response.

Therefore, while route tables are important for network management, they do not contribute to the incident containment efforts in the same way that the other practices do.