There are few situation in office, we need to find out user of an IP address or know IP address of others in your network for the purpose like using SSH and SCP. In such a case, you can use the below steps from Linux terminal: you can get the details of them (with host-name and IP address) by,

$ avahi-browse -rt _workstation._tcp

The above command will list only the computers in your network which uses avahi-daemon (DNS-SD). (all Ubuntu distributions use this ) If you want to know all the IP addresses used in your network irrespective of DNS-SD , you can use arp-scan like below.

$ sudo arp-scan

If not installed by default, you’ll have to install it with sudo apt-get install arp-scan