Final answer:
The best solution to maintain connectivity in case the router or its connection to the ISP fails is to implement a redundant router with automatic failover. This ensures continuous network availability without manual intervention when the primary router goes offline.
Step-by-step explanation:
The question is asking about a strategy to maintain network connectivity in the event of a failure of the company's sole router or its connection to the Internet Service Provider (ISP). The best solution among the provided options to accomplish this is a) Implementing a redundant router with automatic failover. This means having a second router configured to take over the job of the primary router if it goes offline. The redundant router acts as a backup, and automatic failover is the process that seamlessly switches traffic to the redundant router without manual intervention, thereby ensuring continuous network availability.
Option b), adding more switches to the network, would not address connectivity issues relative to the router or its ISP link. Option c), increasing the bandwidth of the existing router, also does not provide a failover solution if the router itself fails. Option d), installing a firewall, is unrelated to router redundancy and cannot prevent router hardware failures. It is designed to provide security, not to maintain connectivity in case of hardware failures.