python telnet to cmts to get ipv6

This is a script to telnet to CMTS-Cisco server to get ipv6 address

The different between python2 and python3 is the byte and str

PYTHON3 we need to use tn.read_until(b"Username:")
PYTHON2 we don't need byte tn.read_until("Username:")

since we need to used byte, so we have to convert to str using decode
we can use decode utf-8 or big5, depend on our OS. If you used CHINESE you have to used BIG5, else ping will not show correct.

Manual Test: 
1.Login to CMTS/Cisco Server
2. used the command to see your ipv6 addres: scm XXX.XXX.XXXX ipv6


1)Method 1 python3 just telnet and get the ipv6 of specfic mac

import getpass
import re
import telnetlib
HOST = "192.168.1.252"
#user = input("Enter your remote account: ")
#password = getpass.getpass()
user='guest'
password='guest'
tn = telnetlib.Telnet(HOST)

tn.read_until(b"Username:")
tn.write(user.encode('ascii') + b"\n")
if password:
    tn.read_until(b"Password:")
    tn.write(password.encode('ascii') + b"\n")

value = tn.read_until(b"Router#")
tn.write(b"scm mac = "AAAA.BBBB.CCCC" ipv6 \n")
value = tn.read_until(b"Router#")
#######################################################
value=value.decode('utf8')
info = "2001"
matchObj = re.match(r'.*'+ info + '(.*)\n',value, re.M|re.DOTALL)
#matchObj=matchObj.decode('big5')

       
if matchObj:
    Ipv6_address = info + matchObj.group(1)
    Ipv6 = Ipv6_address.replace("\n", "")
    print(Ipv6)
    #return Ipv6

else:
    print ("No match!!")  
  

####################################################
        
tn.write(b"exit\n")
#print(tn.read_all().decode('ascii'))

2)Method 2 using function and check telnet reachable or not(python3)

# -*- coding: utf-8 -*-
import telnetlib
import subprocess
import time
import re

def Telnet_Check_reachability(ip):
    ping_count=3
    process = subprocess.Popen(['ping', ip, '-n', str(ping_count)],
                           stdout=subprocess.PIPE,
                           stderr=subprocess.STDOUT)
                      
    process.wait()
    stdout = process.stdout.read()
    stdout=stdout.decode("big5")
    #print stdout
    if "TTL=" in stdout:
        #print "Server reachable"
        successful = 1
    else:
        #print "Server unreachable"
        successful = 0
    return successful

def Login_Telnet(HOST,username,password):
    try:
        tn=""
        reachability=Telnet_Check_reachability(HOST)
        if (reachability==1):
            tn = telnetlib.Telnet(HOST,23)
            tn.read_until(b"Username:")
            #tn.write(username + "\n")
            tn.write(username.encode('ascii') + b"\n")
            if password:
                tn.read_until(b"Password:")
                #tn.write(password + "\n")
                tn.write(password.encode('ascii') + b"\n")
            time.sleep(3)
            return tn
    except IOError:
        print ("Telnet " + HOST + " failed. Please check the server connection")

def telnet_To_CMTS(Client_IP, Client_Name, Client_Pwd, MAC):
    tn =Login_Telnet(Client_IP, Client_Name, Client_Pwd)
    if "telnetlib" in str(tn):
        time.sleep(1)
        value = tn.read_until(b"Router#")
        command = "scm " + MAC + " ipv6\n"
        tn.write(command.encode('ascii') + b"\n")
        #tn.write(command)
        
        value = tn.read_until(b"Router#")
        #print value
        tn.close()
        time.sleep(1)

        info = "2001"
       
        #value=str(value)
        value=value.decode('utf8')
        
        matchObj = re.match(r'.*'+ info + '(.*)\n',value, re.M|re.DOTALL)
       
        if matchObj:
            Ipv6_address = info + matchObj.group(1)
            Ipv6 = Ipv6_address.replace("\n", "")
            return Ipv6
        else:
           print ("No match!!")    
        
    else:
        print ("Telnet failed")
ip ="192.168.1.252"
username = "guest"
password = "guest"
mac = "AAAA.BBBB.CCCC"
new_IPv6 = telnet_To_CMTS(ip, username, password, mac)
print (new_IPv6)

3)Method 3 same as method2 using python2

# -*- coding: utf-8 -*-
import telnetlib
import subprocess
import time
import re

def Telnet_Check_reachability(ip):
    ping_count=3
    process = subprocess.Popen(['ping', ip, '-n', str(ping_count)],
                           stdout=subprocess.PIPE,
                           stderr=subprocess.STDOUT)
                      
    process.wait()
    stdout = process.stdout.read()
    #print stdout
    if "TTL=" in stdout:
        #print "Server reachable"
        successful = 1
    else:
        #print "Server unreachable"
        successful = 0
    return successful

def Login_Telnet(HOST,username,password):
    try:
        tn=""
        reachability=Telnet_Check_reachability(HOST)
        if (reachability==1):
            tn = telnetlib.Telnet(HOST,23)
            tn.read_until("Username:")
            tn.write(username + "\n")
            if password:
                tn.read_until("Password:")
                tn.write(password + "\n")
            time.sleep(3)
            return tn
    except IOError:
        print "Telnet " + HOST + " failed. Please check the server connection"

def telnet_To_CMTS(Client_IP, Client_Name, Client_Pwd, MAC):
    tn =Login_Telnet(Client_IP, Client_Name, Client_Pwd)
    if "telnetlib" in str(tn):
        time.sleep(1)
        value = tn.read_until("Router#")
        command = "scm " + MAC + " ipv6\n"
        tn.write(command)
        value = tn.read_until("Router#")
        #print value
        tn.close()
        time.sleep(1)

        info = "2001"

        matchObj = re.match(r'.*'+ info + '(.*)\n',value, re.M|re.DOTALL)
        if matchObj:
            Ipv6_address = info + matchObj.group(1)
            Ipv6 = Ipv6_address.replace("\n", "")
            return Ipv6

        else:
           print "No match!!"    
    else:
        print "Telnet failed"


ip ="192.168.1.252"
username = "guest"
password = "guest"
mac = "AAAA.BBBB.CCCC"
new_IPv6 = telnet_To_CMTS(ip, username, password, mac)
print new_IPv6