Cisco Certified Network Associate (CCNA) Practice Exam 2026 - Free CCNA Practice Questions and Study Guide

The correct choice identifies preshared keys as the method used for IKE remote peer authentication that relies on manually configured keys. Preshared keys are a common and straightforward method of establishing initial trust between two parties in a secure communication setup, such as in VPNs or secure IP communication.

In this authentication method, both peers must manually configure the same key, which is used to authenticate each other. This simplicity makes preshared keys a popular choice for small networks or when a lightweight setup is preferred, as it avoids the complexities involved in managing certificates or a key infrastructure.

The other methods mentioned, while they are legitimate forms of authentication, do not utilize manually configured keys. Digital Certificate Authentication typically relies on a certificate authority to issue certificates and validate identities. Public Key Infrastructure involves a more complex framework for managing public and private key pairs, which also does not require manual key configuration in the same direct manner. Symmetric Key Authentication, while it does use keys, usually refers to methods where keys are generated and exchanged through other secure means, rather than being manually configured by the administrator.

Thus, preshared keys stand out as the unique choice that fits the criteria of using manually configured keys for IKE remote peer authentication.