Find open ports on the Linux server using a script
Create a .sh file with below script and set execute permission for the scrip file.
#vi portscan.sh
#!/bin/bash
#The port numbers
- PORT1=21 #ftp
- PORT2=22 #ssh
- PORT3=25 #smtp
- PORT4=53 #dns
- PORT5=80 #http
- PORT6=110 #POP3
- PORT7=143 #IMAP
- PORT8=443 #https
- PORT9=1433 #MSSQL
- PORT10=3306 #MYSQL
- PORT11=3389 #Microsoft-RDP
- PORT12=5432 #PostgreSQL
read -p “Enter the Server IP/HOSTNAME : ” HOSTNAME #Enter the Host Name to check the Open Ports
echo “”
echo “Checking open/closed ports on the host $HOSTNAME”, Please wait….
echo “”
if ping -c2 $HOSTNAME |grep -i “time=”
then
echo $HOSTNAME is up
else
echo “$HOSTNAME is down or unable to ping”
fi
echo “”
echo “Checking the port status of $HOSTNAME”, Please wait….
echo “”
if nmap -p$PORT1 $HOSTNAME | grep -q open
then
echo $PORT1 is open
else
echo $PORT1 is down
fi
if nmap -p$PORT2 $HOSTNAME | grep -q open
then
echo $PORT2 is open
else
echo $PORT2 is down
fi
if nmap -p$PORT3 $HOSTNAME | grep -q open
then
echo $PORT3 is open
else
echo $PORT3 is down
fi
if nmap -p$PORT4 $HOSTNAME | grep -q open
then
echo $PORT4 is open
else
echo $PORT4 is down
fi
if nmap -p$PORT5 $HOSTNAME | grep -q open
then
echo $PORT5 is open
else
echo $PORT5 is down
fi
if nmap -p$PORT6 $HOSTNAME | grep -q open
then
echo $PORT6 is open
else
echo $PORT6 is down
fi
if nmap -p$PORT7 $HOSTNAME | grep -q open
then
echo $PORT7 is open
else
echo $PORT7 is down
fi
if nmap -p$PORT8 $HOSTNAME | grep -q open
then
echo $PORT8 is open
else
echo $PORT8 is down
fi
if nmap -p$PORT9 $HOSTNAME | grep -q open
then
echo $PORT9 is open
else
echo $PORT9 is down
fi
if nmap -p$PORT10 $HOSTNAME | grep -q open
then
echo $PORT10 is open
else
echo $PORT10 is down
fi
if nmap -p$PORT11 $HOSTNAME | grep -q open
then
echo $PORT11 is open
else
echo $PORT11 is down
fi
if nmap -p$PORT12 $HOSTNAME | grep -q open
then
echo $PORT12 is open
else
echo $PORT12 is down
fi
# chmod +x portscan.sh
# sh portscan.sh
Enter the Server IP/HOSTNAME : localhost (any server name or ip address)
(You will see the output as below)
Checking open/closed ports on the host localhost, Please wait….
64 bytes from 127.0.0.1: icmp_seq=0 ttl=64 time=0.037 ms
64 bytes from 127.0.0.1: icmp_seq=1 ttl=64 time=0.039 ms
localhost is up
Checking the port status of localhost, Please wait….
- 21 is down
- 22 is open
- 25 is open
- 53 is down
- 80 is down
- 110 is down
- 143 is down
- 443 is down
- 1433 is down
- 3306 is down
- 3389 is down
Hope this helped in finding the open ports on Linux using a script.
Here is a related post you may be interested in: How to Fix – When Xenserver Host Stuck in Maintenance Mode
To get more updates you can follow us on Facebook, Twitter, LinkedIn
Subscribe to get free blog content to your Inbox
