Ping in Network Discovery

By | March 10, 2020

Network discovery is a process to find other computers and devices on some network and to get obtainable information about them. The discovery procedure is based on sending out request messages over and analyzing responses from remote devices. ICMP (Internet Control Message Protocol) is most frequently method detect remote device. Below is presented simple Linux shell script to find pingable devices withing appropriate IPv4 range.


#! /bin/bash
start_message()
{
   echo “Correct argument required, example: 192.168.1.0-127”
   exit 1
}

echo “Pinging IP range”
if [ $# -eq 0 ]; then
   start_message
fi
IPRANGE=$(echo $1 | grep -v ‘[A-Za-z]’ | grep -oE ‘(\b[0-9]{1,3}\.){3}[0-9]{1,3}-[0-9]{1,3}’)
if [ “$IPRANGE” == “” ]; then
   echo “Wrong argument: $1”
   start_message
fi
echo “Ping this IP range: $IPRANGE”
IPBASE=$(echo $IPRANGE | grep -oE ‘(\b[0-9]{1,3}\.){2}[0-9]{1,3}’)
# echo $IPBASE
IPSTART=$(echo $IPRANGE | grep -oE ‘\b[0-9]{1,3}-‘ | grep -oE ‘\b[0-9]{1,3}’)
#echo $IPSTART
IPEND=$(echo $IPRANGE | grep -oE ‘\b-[0-9]{1,3}’ | grep -oE ‘\b[0-9]{1,3}’)
# echo $IPEND
for param in `seq $IPSTART $IPEND`; do
   IPADDR=$IPBASE.$param
   RESULT=$(ping $IPADDR -c 1 -i 1 | grep icmp_seq=1 | grep -i -v Unreachable | grep -v ‘100% packet loss’)
   if [ “$RESULT” != “” ]; then
      echo “$IPADDR ($RESULT)”
      fi
done

The script was tested on CentOS and Ubuntu. The script can be download from icmpscan.sh.zip.


The result of scanning IP range from 149.56.221.1 to 149.56.221.110 (The list of pingable IP addresses):


# ./icmpscan.sh 149.56.221.1-110
Pinging IP range
Ping this IP range: 149.56.221.1-110
149.56.221.17 (64 bytes from 149.56.221.17: icmp_seq=1 ttl=49 time=51.6 ms)
149.56.221.18 (64 bytes from 149.56.221.18: icmp_seq=1 ttl=49 time=53.3 ms)
149.56.221.19 (64 bytes from 149.56.221.19: icmp_seq=1 ttl=48 time=53.1 ms)
149.56.221.20 (64 bytes from 149.56.221.20: icmp_seq=1 ttl=49 time=52.9 ms)
149.56.221.21 (64 bytes from 149.56.221.21: icmp_seq=1 ttl=49 time=53.7 ms)
149.56.221.22 (64 bytes from 149.56.221.22: icmp_seq=1 ttl=48 time=54.2 ms)
149.56.221.23 (64 bytes from 149.56.221.23: icmp_seq=1 ttl=48 time=53.4 ms)
149.56.221.24 (64 bytes from 149.56.221.24: icmp_seq=1 ttl=49 time=53.1 ms)
149.56.221.25 (64 bytes from 149.56.221.25: icmp_seq=1 ttl=49 time=50.6 ms)
149.56.221.26 (64 bytes from 149.56.221.26: icmp_seq=1 ttl=48 time=52.7 ms)
149.56.221.27 (64 bytes from 149.56.221.27: icmp_seq=1 ttl=48 time=53.0 ms)
149.56.221.28 (64 bytes from 149.56.221.28: icmp_seq=1 ttl=48 time=53.0 ms)
149.56.221.29 (64 bytes from 149.56.221.29: icmp_seq=1 ttl=49 time=54.2 ms)
149.56.221.30 (64 bytes from 149.56.221.30: icmp_seq=1 ttl=49 time=53.8 ms)
149.56.221.38 (64 bytes from 149.56.221.38: icmp_seq=1 ttl=50 time=52.4 ms)
149.56.221.56 (64 bytes from 149.56.221.56: icmp_seq=1 ttl=50 time=67.8 ms)
149.56.221.57 (64 bytes from 149.56.221.57: icmp_seq=1 ttl=50 time=54.0 ms)
149.56.221.65 (64 bytes from 149.56.221.65: icmp_seq=1 ttl=50 time=55.7 ms)
149.56.221.66 (64 bytes from 149.56.221.66: icmp_seq=1 ttl=49 time=59.2 ms)
149.56.221.67 (64 bytes from 149.56.221.67: icmp_seq=1 ttl=50 time=54.0 ms)
149.56.221.68 (64 bytes from 149.56.221.68: icmp_seq=1 ttl=49 time=56.3 ms)
149.56.221.69 (64 bytes from 149.56.221.69: icmp_seq=1 ttl=50 time=59.7 ms)
149.56.221.70 (64 bytes from 149.56.221.70: icmp_seq=1 ttl=49 time=63.9 ms)
149.56.221.75 (64 bytes from 149.56.221.75: icmp_seq=1 ttl=48 time=53.2 ms)
149.56.221.77 (64 bytes from 149.56.221.77: icmp_seq=1 ttl=49 time=52.6 ms)
149.56.221.78 (64 bytes from 149.56.221.78: icmp_seq=1 ttl=49 time=52.7 ms)
149.56.221.80 (64 bytes from 149.56.221.80: icmp_seq=1 ttl=49 time=52.2 ms)
149.56.221.81 (64 bytes from 149.56.221.81: icmp_seq=1 ttl=49 time=52.7 ms)
149.56.221.82 (64 bytes from 149.56.221.82: icmp_seq=1 ttl=48 time=50.2 ms)
149.56.221.83 (64 bytes from 149.56.221.83: icmp_seq=1 ttl=48 time=52.6 ms)
149.56.221.84 (64 bytes from 149.56.221.84: icmp_seq=1 ttl=49 time=54.7 ms)
149.56.221.85 (64 bytes from 149.56.221.85: icmp_seq=1 ttl=49 time=56.8 ms)
149.56.221.86 (64 bytes from 149.56.221.86: icmp_seq=1 ttl=48 time=57.6 ms)
149.56.221.87 (64 bytes from 149.56.221.87: icmp_seq=1 ttl=49 time=56.4 ms)
149.56.221.88 (64 bytes from 149.56.221.88: icmp_seq=1 ttl=48 time=50.0 ms)
149.56.221.89 (64 bytes from 149.56.221.89: icmp_seq=1 ttl=48 time=50.5 ms)
149.56.221.90 (64 bytes from 149.56.221.90: icmp_seq=1 ttl=48 time=56.8 ms)
149.56.221.91 (64 bytes from 149.56.221.91: icmp_seq=1 ttl=48 time=54.7 ms)
149.56.221.92 (64 bytes from 149.56.221.92: icmp_seq=1 ttl=49 time=53.1 ms)
149.56.221.93 (64 bytes from 149.56.221.93: icmp_seq=1 ttl=48 time=53.6 ms)
149.56.221.94 (64 bytes from 149.56.221.94: icmp_seq=1 ttl=49 time=53.4 ms)
149.56.221.95 (64 bytes from 149.56.221.95: icmp_seq=1 ttl=49 time=52.4 ms)

For some ping version icmp_seq must be replaced with icmp_req in "grep icmp_seq=1" statement.


# ./icmpscan.sh 192.168.2.1-254
Pinging IP range
Ping this IP range: 192.168.2.1-254
192.168.2.1 (64 bytes from 192.168.2.1: icmp_req=1 ttl=64 time=3.96 ms)
192.168.2.11 (64 bytes from 192.168.2.11: icmp_req=1 ttl=128 time=9.78 ms)
192.168.2.14 (64 bytes from 192.168.2.14: icmp_req=1 ttl=128 time=0.499 ms)
192.168.2.20 (64 bytes from 192.168.2.20: icmp_req=1 ttl=255 time=9.49 ms)
192.168.2.113 (64 bytes from 192.168.2.113: icmp_req=1 ttl=64 time=14.3 ms)
192.168.2.169 (64 bytes from 192.168.2.169: icmp_req=1 ttl=64 time=0.037 ms)
192.168.2.215 (64 bytes from 192.168.2.215: icmp_req=1 ttl=64 time=26.7 ms)
192.168.2.247 (64 bytes from 192.168.2.247: icmp_req=1 ttl=64 time=17.8 ms)

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