Which command is used to set the default router address on a Linux system?

The command used to set the default router address on a Linux system is aptly handled by the route command. This command manipulates the IP routing table and allows users to add, delete, or change routes, including setting the default gateway.

When you use the route command to set a default gateway, you typically do so by specifying the destination as "default" along with the gateway address. This action tells the Linux system to direct any traffic destined for addresses not explicitly defined in the routing table to the specified gateway.

The other options, while related to network operations, serve different purposes. The 'ip' command is part of a more modern suite of tools for network configuration and can also be utilized to manipulate routes, but its syntax is different and broader. 'netstat' is primarily used for displaying network connections, routing tables, interface statistics, and more—it does not modify the routing table. 'traceroute' is a diagnostic tool used to track the path packets take across the network and does not interact with routing configurations.

Thus, using the route command for setting the default router address aligns perfectly with its intended function within Linux networking.