The uname command can print some basic information about your Linux system. This information can include:
Operating system name (i.e., Linux)
System's host name
Linux release number
Current date and time
The following is an example of the uname -a command (the -a prints all the information at once):
$ uname -a
Linux mycomputer 2.4.6-3.1 #1 Sat Oct 27 19:09:11 EDT 2001 i686 unknown
The system's hostname is used to identify your computer (in particular, it is used by remote systems to contact you over a network). The Linux release number (2.4.6-3.1) identifies the release of the Linux kernel that you have installed. Check this number to make sure you have the latest kernel. You can change your computer name using the hostname command as follows:
# hostname yourcomputer
Hostname is read automatically
The hostname is read automatically by different programs that need to indicate what computer is being used.
For example, your shell command line prompt probably automatically displays the hostname. You can also print other information that relates to how your computer is named from the perspective of the network. For example, dnsdomainname lists your domain name (used for the Internet). If your computer uses NIS services, you can print your NIS domain name with the domainname command.
arp-a command output
arpwatch: Contains the arpwatch utility for tracking Ethernet/IP address pairings.