My old ISP use to change my external IP address all the time and to keep my DNS name on track I wrote this script:

!/usr/bin/python

import smtplib import urllib2 import time import sys

def send_email(): try: server = smtplib.SMTP('smtp', 587)#smtp address and port number

server.starttls()
#Next, log in to the server
server.login("smtp username", "password")#username and password for smtp

#def emailSend(ipaddress):
to\_addr="your email address"
subject="IPaddress is changed"
message="this is from your webserver:" + html
from\_addr="you@gmail.com"

header  = 'From: %s\\n' % from\_addr
header += 'To: %s\\n' % to\_addr
header += 'Subject: %s\\n\\n' % subject
message = header + message

#Send the mail
#msg = "\\nHello!" # The /n separates the message from the headers
time.sleep(10)  
print "wait few seconds..."
server.sendmail(from\_addr, to\_addr, message)
#server.sendmail(from\_addr, to\_addr, message)
print "done."
return True 

except:
print "Unexpected error:", sys.exc_info()[0] return False

response = urllib2.urlopen('http://myip.dnsdynamic.org') html = response.read() print html

f = open("/root/myip.txt", "r"); sss = f.read() print f.read() if sss != html: print 'write' ff = open("/root/myip.txt", "w"); ff.write(html) ff.close() if send_email() == False: send_email() else: print 'all good'

f.close()

I hope it will be useful to some one else! Enjoy.