Answer:
from socket import *
hostname = input('Enter the host to be scanned: ')
ip_add = gethostbyname(hostname)
connections = [ ]
for i in range(133, 136):
s = socket(AF_INET, SOCK_STREAM)
conn = s.connect_ex((ip_add, i))
print(conn)
connections.append(conn)
if 0 in connections:
print ('Host is online')
s.close()
else:
print ('system is unreachable')
Explanation:
The python source code above scans for all the available range of ports in the provided hostname, if any port is available, the host is online else the program print the error message "system is unreachable.