To address a maintenance problem, a vendor needs remote access to a critical network. The
MOST secure and effective solution is to provide the vendor with a:
Secure Shell (SSH-2) tunnel for the duration of the problem.
two-factor authentication mechanism for network access.
virtual private network (VPN) account for the duration of the vendor support contract.
For granting temporary access to the network, a Secure Shell (SSH-2) tunnel is the best approach.
It has auditing features and allows restriction to specific access points. Choices B, C and D all give
full access to the internal network. Two-factor authentication and virtual private network (VPN)
provide access to the entire network and are suitable for dedicated users. Dial-in access would
need to be closely monitored or reinforced with another mechanism to ensure authentication to
achieve thesame level of security as SSH-2.