telnet-template.py

#Open telnet connection to devices
def open_telnet_conn(ip):
    #Change exception message
    try:
        #Define telnet parameters
        username = 'teopy'
        password = 'python'
        TELNET_PORT = 23
        TELNET_TIMEOUT = 5
        READ_TIMEOUT = 5
        
        #Logging into device
        connection = telnetlib.Telnet(ip, TELNET_PORT, TELNET_TIMEOUT)
        
        output = connection.read_until("name:", READ_TIMEOUT)
        connection.write(username + "\n")
        
        output = connection.read_until("word:", READ_TIMEOUT)
        connection.write(password + "\n")
        time.sleep(1)	
        
        #Setting terminal length for entire output - no pagination
        connection.write("terminal length 0\n")
        time.sleep(1)
        
        #Entering global config mode
        connection.write("\n")
        connection.write("configure terminal\n")
        time.sleep(1)
        
        #Open user selected file for reading
        selected_cmd_file = open(cmd_file, 'r')
            
        #Starting from the beginning of the file
        selected_cmd_file.seek(0)
        
        #Writing each line in the file to the device
        for each_line in selected_cmd_file.readlines():
            connection.write(each_line + '\n')
            time.sleep(1)
    
        #Closing the file
        selected_cmd_file.close()
        
        #Test for reading command output
        #output = connection.read_very_eager()
        #print output
        
        #Closing the connection
        connection.close()
        
    except IOError:
        print "Input parameter error! Please check username, password and file name."
		
#Calling the Telnet function
open_telnet_conn(ip)