Without sudo this scan would not return the manufacturer information, for example. You can run this scan without using sudo, but using sudo ensures it can extract as much information as possible. sudo nmap -sn 192.168.4.0/24Īfter a short wait, the output is written to the terminal window. The parameter “192.168.4.0/24” translates as “start at IP address 192.168.4.0 and work right through all IP addresses up to and including 192.168.4.255”. The “/24” tells nmap to scan the entire range of this network.

That is the first possible IPAddress on this network. The IP address we’re going to use is the one we obtained using the ip command earlier, but the final number is set to zero. Don’t be surprised when nothing visible happens for a minute or so. It does all of its probing and reconnaissance work first and then presents its findings once the first phase is complete. Of course, the more devices you have on the network, the longer it will take. It will do a lightweight, quick scan.Įven so, it can take a little time for nmap to run. This tells nmap to not probe the ports on the devices for now. We’re going to use the -sn (scan no port) option. It can deduce a lot about the device it is probing by judging and interpreting the type of responses it gets. It works by sending various network messages to the IP addresses in the range we’re going to provide it with it. RELATED: How Do IP Addresses Work? Get Started with nmap Happily, nmap works with that notation, so we have what we need to start to use nmap. And because the largest number you can hold in an 8-bit binary number is 255, the IP address range for this network will be 192.168.4.0 through to 192.168.4.255.Īll of that is encapsulated in the “/24”. This subnet mask informs the hardware that the first three numbers of the IP address will identify the network and the last part of the IP address identifies the individual devices. The subnet mask and the IP address are used to indicate which part of the IP address identifies the network, and which part identifies the device. The “/24” means that there are three consecutive sets of eight 1’s in the subnet mask. The IP address of this computer is “192.168.4.25”. In the bottom section of the output, you will find your ip address. Handily, Linux provides a command called ip and it has an option called addr (address).

Unknown router on my network