To change the address of the default gateway on a Linux server, which tool should be used?

The appropriate tool to change the address of the default gateway on a Linux server is IFconfig. This command-line utility is used to configure network interfaces, allowing system administrators to set parameters such as IP addresses, subnet masks, and gateways. By using IFconfig, you can effectively modify the network settings, including the default gateway, which determines where packets are sent when no specific route is defined for a given destination.

Other options do not fit this context. For instance, Ipconfig and Winipcfg are Windows-specific commands used for displaying and modifying network configuration on Windows operating systems, making them unsuitable for use in a Linux environment. Tracert, meanwhile, is employed to trace the path packets take to a network destination, and while it’s useful for diagnosing network issues, it doesn't have the capability to change network interface settings or the default gateway. Therefore, IFconfig stands out as the correct tool for managing network configurations on Linux systems.