Answer Description
The computer is likely a Linux/Unix (*nix) machine, ifconfig is the appropriate command to find the IP address in a *nix OS. Netstat will show active connections but not the IP address. Nslookup is for querying DNS. Tracert is not likely to work on a *nix box, nor will it display for IP since it is used for showing path information to a remote system.
Wikipedia
ifconfig (short for interface config) is a system administration utility in Unix-like operating systems for network interface configuration The utility is a command-line interface tool and is also used in the system startup scripts of many operating systems It has features for configuring, controlling, and querying TCP/IP network interface parameters Ifconfig originally appeared in 42BSD as part of the BSD TCP/IP suite
Ifconfig - Wikipedia, the free encyclopedia