If you ever wanted to do host discovery while no specific network scanning tools were available (e.g. nmap), or you wanted to avoid creating a script file (e.g. due to having no write permissions)? Here are a couple of useful commands depending on the OS of your choice:
Windows OS:
for /L %i IN (1,1,254) DO ping -n 1 -w 1 192.168.1.%i| FIND /i "Reply" >> IPs.txt
Note: command prompt has a limitation when asked to return the exact string using regex and returns the whole line. Here is an example of replacing find with findstr in order to use a regular expression (regex).
findstr /r "[0-9][0-9]*\.[0-9][0-9]*\.[0-9][0-9]*\.[0-9][0-9]*"
The regular expression can still be useful in cases such as:
ipconfig | findstr /r "[0-9][0-9]*\.[0-9][0-9]*\.[0-9][0-9]*\.[0-9][0-9]*"
Linux OS:
for i in {1..254}; do (ping -c 1 -i 1 192.168.1.$i >/dev/null && echo "192.168.1.$i" &); done
Note: The above command will only list the discovered IP address, without any additional text.
Tip/Trick: Did you know you can use apr to achieve the same results but much faster. This seems to be reliable under Linux. The following command will list the discovered host on your network, including any additional information per IP (including the IPv6 address).
for ip in $(seq 1 254); do arp -n 192.168.1.$ip | grep on; done
The following command however, will list only the IP addresses without any additional text (also avoiding to specify the IP range twice)
for ip in $(seq 1 254); do arp -n 192.168.1.$ip | grep on | grep -Eo '[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}' ; done
Windows OS:
for /L %i IN (1,1,254) DO ping -n 1 -w 1 192.168.1.%i| FIND /i "Reply" >> IPs.txt
Note: command prompt has a limitation when asked to return the exact string using regex and returns the whole line. Here is an example of replacing find with findstr in order to use a regular expression (regex).
findstr /r "[0-9][0-9]*\.[0-9][0-9]*\.[0-9][0-9]*\.[0-9][0-9]*"
The regular expression can still be useful in cases such as:
ipconfig | findstr /r "[0-9][0-9]*\.[0-9][0-9]*\.[0-9][0-9]*\.[0-9][0-9]*"
Linux OS:
for i in {1..254}; do (ping -c 1 -i 1 192.168.1.$i >/dev/null && echo "192.168.1.$i" &); done
Note: The above command will only list the discovered IP address, without any additional text.
Tip/Trick: Did you know you can use apr to achieve the same results but much faster. This seems to be reliable under Linux. The following command will list the discovered host on your network, including any additional information per IP (including the IPv6 address).
for ip in $(seq 1 254); do arp -n 192.168.1.$ip | grep on; done
The following command however, will list only the IP addresses without any additional text (also avoiding to specify the IP range twice)
for ip in $(seq 1 254); do arp -n 192.168.1.$ip | grep on | grep -Eo '[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}' ; done
