- to check if the DNS service is running
- to connect to the Cisco server
- to test if the Cisco server is reachable
- to discover the transmission time needed to reach the Cisco server
nslookup command queries DNS servers to find out the IP address or addresses associated with the domain name cisco.com. A successful result indicates that the DNS configuration on the PC is functional, and also indicates the IP address for the domain name being displayed. The command does not try connect to the actual Cisco host directly.