(NSLOOKUP) In Mac OS X, how do I find out the IP address or domain name of another networked device?
In Mac OS X, to find the IP address or domain name of another networked device, use the Network Utility, which is installed in the Utilities folder, which in turn is inside the Applications folder. With it, you may query a DNS server for information on specific computers. The Network Utility is able to make detailed queries about hosts, but to make a simple one follow these steps:
Note: In order to find a computer or device's domain name, you must already know its IP address; conversely, to find the IP address, you must already know the domain name.
Launch the Network Utility.
In the Network Utility window, click the Lookup tab.
In the field under "Please enter an internet address to lookup", enter the IP address or domain name of the computer you are looking up.
In the pop-up menu next to "Select the information to lookup:", select Default Information.
Uncheck the checkbox next to Use "dig" in place of "nslookup".
Click the Lookup button.
This will show the IP address of the domain you entered and will also show what name-servers you are using to get the IP address.
(PING) In Mac OS X, how can I check to see if a computer is on the network?
In Mac OS X, to see if a computer is on the network, use the Network Utility and ping the remote host. A ping is a small packet of data sent to the remote host and then sent back by the recipient computer. If the computer is not on the network, it will not be able to respond to the packet. To use the Network Utility, follow these instructions:
Launch the Network Utility. It should be in the Utilities folder, which is in the Applications folder.
In the Network Utility window, click the Ping tab.
In the field under "Please enter the network address to ping", enter the IP address or domain name of the computer you want to ping.
Click the radio button next to Send only ___ pings.
In the Send only ___ pings box, type the number of packets you would like the Network Utility to send. The default is ten, and that should be sufficient in all but the most congested network conditions.
Click the Ping button.
The Network Utility will begin pinging the host. If the host is on the network, the packets will be listed in the Network Utility as they are returned. If no packets are returned, then either the computer is off the network or there are network problems between your computer and the remote host.
(TRACEROUTE) For a more definitive answer, use the Network Utility's traceroute function. The traceroute function will attempt to determine where the network difficulty is occurring. Follow these directions:
Click the Traceroute tab.
In the field under "Please enter the network address to trace an internet route to", enter the IP address or domain name of the remote host.
Click the Trace button.
Note: In some cases, a computer will respond to a ping but will be unreachable by other network tools, such as telnet, rlogin, or Web browsers.