Finding All Hosts On the LAN From Linux / Windows Workstation

by Vivek Gite [Last updated: March 5, 2008]

Q. How do I find out if all host computers on the LAN are alive or dead from a Linux or Windows XP computer? My network subnet range is 192.168.1.0/24 and I'm using dual boot Debian Linux / XP SP2 computer.

A.You can use normal ping command and shell script loop statement to print the list of all LAN computers from a shell prompt.

Linux / UNIX one liner to ping all hosts on the LAN

Type the following command, enter:
$ for ip in $(seq 1 254); do ping -c 1 192.168.1.$ip>/dev/null; [ $? -eq 0 ] && echo "192.168.1.$ip UP" || : ; done
Output:

192.168.1.1 UP
192.168.1.1 UP
192.168.1.2 UP
192.168.1.5 UP
......
...
..
192.168.1.254 UP

See previous article: Simple Linux and UNIX system monitoring with ping command and scripts.

A Note About Windows Workstation

If you are using Windows 2000 / XP / Vista, try something as follows at DOS / NT command prompt (Start > Run > CMD > Enter key):
c:> for /L %I in (1,1,254) DO ping -w 30 -n1 192.168.1.%I | find "Reply"
Read cmd.exe help page and batch scripting documentation for more information.

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{ 12 comments… read them below or add one }

1 Casper 03.05.08 at 6:37 pm: You would probably use
"for ip in $(perl -e '$,="\n"; print 0 .. 8;') ; do ping -c 1 192.168.1.$ip>/dev/null; [ $? -eq 0 ] && echo “192.168.1.$ip UP” || : ; done”
on non GNU/Linux system, as seq does not exist on Solaris and OSX.
2 Casper 03.05.08 at 6:41 pm: Ups, this is nicer, and faster.
for ip in $(perl -e '$,="\n"; print 1 .. 254;') ; do ping -t 1 -c 1 192.168.1.$ip>/dev/null; [ $? -eq 0 ] && echo “192.168.1.$ip UP” || : ; done

I’ve added a 1 sec. timeout on ping.
3 richard 03.05.08 at 8:28 pm: Do you know fping ?
$ sudo apt-get install fping
$ fping -a -g 192.168.1.0/24 2> /dev/null
4 vivek 03.05.08 at 9:27 pm: @Casper,
Thanks for sharing perl only code.

@Richard,
Sure, fping was covered some time ago..
5 Scott Carlson 03.06.08 at 2:41 am: I generally just use this “ping -b 192.168.1.255″ Which broadcasts a ping to the whole network at once.
6 Topper 03.06.08 at 8:38 am: What about Windows machines with MS firewall which default forbid ICMP replay ?
Maybe must use ARP cache after ping
7 Z3n0 03.06.08 at 9:30 am: another way…

for ((ip=1;ip/dev/null; [ $? -eq 0 ] && echo “192.168.1.$ip UP” || : ; done
8 matthias 03.06.08 at 9:40 am: If a host on your local network won’t answer on a ping request you could try arping, which does an arp request.
arping 192.168.1.1 ARPING 192.168.1.1 from 192.168.1.226 eth0 Unicast reply from 192.168.1.1 [00:01:02:xx:xx:xx] 0.668ms

Another method is simply using nmap:
nmap -sP 192.168.1.0/24
9 Z3n0 03.06.08 at 10:13 am: Something wrong with prev. comment… (< and > char)
for (( ip=1 ; ip<=254 ; ip++ )); do ping -c 1 -t 1 192.168.1.$ip>/dev/null; [ $? -eq 0 ] && echo “192.168.1.$ip UP” || : ; done
10 phillip 03.07.08 at 12:42 pm: Using nast ?

http://netsecure.alcpress.com/nast/

nast -m

best.
11 sg 03.07.08 at 4:29 pm: another option is installing arpwatch.
12 suren 03.16.08 at 4:28 am: wont this command do ???

nbtscan 10.0.0.1-125

this checks all the computers whose ip address are in the range of 10.0.0.1 to 10.0.0.125 and displays only those which are ON and connected to the network !