diff --git a/README.md b/README.md
index a8dcc8b..3b678bc 100644
--- a/README.md
+++ b/README.md
@@ -1,42 +1,51 @@
-# template-python
+# cisco-management
 
-Template repository for projects on python
+Wireguard management and monitoring utils.
 
-* [`script.py`](https://git.hmp.today/pavel.muhortov/template-python#script-py)
+* [`cisco-port-failover`.py](https://git.hmp.today/pavel.muhortov/cisco-management#cisco-port-failover-py)
 
 ____
 
-## `script.py`
+## `cisco-port-failover`.py
 
 **Description:**  
-> returning current username if privileged rights are exist  
-> or  
-> returning error, if privileged rights are not exist
+> Cisco ports switching if the target is unreachable.  
 
 **Dependencies:**  
 >
-> * Python 3 (tested version 3.9.5)
+> * privileged rights
+> * [Python 3](https://www.python.org/downloads/) (tested version 3.9.5 on [Debian GNU/Linux 11](http://ftp.debian.org/debian/dists/bullseye/))
+> * [paramiko](https://www.paramiko.org/) Python 3 module (tested version 3.1.0)
 
-|  PARAMETERS | DESCRIPTION | DEFAULT|
-|-------------|-------------|--------|
-|**[-s,--show]**|"" - execution with pauses.<br/>"qn" - execution without pauses.||
-|**[-c,--conf]**|path to configuration file|`./script.conf`|
+| PARAMETERS   |       DESCRIPTION      |    DEFAULT    |
+|--------------|------------------------|---------------|
+|**[--host]**|cisco host address|**REQUIRED**|
+|**[--port]**|cisco ssh port|`22`|
+|**[--user]**|cisco ssh username|`cisco`|
+|**[--pass]**|cisco ssh password|`cisco`|
+|**[--p_en]**|cisco enable mode password|the same ssh password|
+|**[--check]**|ping target host|`None`|
+|**[--iface]**|cisco target interface|`None`|
+|**[--wait]**|delay in seconds between commands|`0.05`|
+|**[--log_root]**|path to log directory|the same script path|
+|**[--log_level]**|DEBUG, INFO, WARNING, ERROR, CRITICAL|`INFO`|
 
-Example usage in terminal with Python on Linux:
+Example usage with cron:  
 
-```shell
-python3 ./script.py
+```bash
+# install dependencies
+sudo pip install paramiko
+# download
+sudo wget https://git.hmp.today/pavel.muhortov/cisco-management/raw/branch/master/cisco-port-failover.py -O /usr/local/bin/cisco-port-failover.py
+sudo chmod +x /usr/local/bin/cisco-port-failover.py
 ```
 
-Example usage in terminal with make the script executable on Linux:
-
-```shell
-chmod u+x ./script.py
-script.py -s qn -c ./script.conf
+```bash
+# sudo crontab -e
+*/2 * *  *  * /usr/bin/python3 /usr/local/bin/cisco-port-failover.py --host 10.0.0.1 --user USER --pass PASS --check 10.0.1.1 --check 10.0.1.2 --check 10.0.1.3 --iface Gi1/0/1 --iface Gi1/0/2 --log_root /var/log
 ```
 
-Example usage in terminal with Python on Windows:
-
-```shell
-python .\script.py
+```bash
+# watching
+tail -f /var/log/cisco-port-failover.log
 ```
diff --git a/cisco-port-failover.py b/cisco-port-failover.py
new file mode 100644
index 0000000..292fe65
--- /dev/null
+++ b/cisco-port-failover.py
@@ -0,0 +1,376 @@
+#!/usr/bin/env python3
+# pylint: disable=C0103
+
+"""Cisco port failover. Cisco ports switching if the target is unreachable.
+"""
+
+import datetime
+import inspect
+import logging
+import re
+from argparse import ArgumentParser
+from os import path, sep
+from subprocess import Popen, PIPE, STDOUT
+from sys import modules, platform
+from time import sleep
+from paramiko import SSHClient, AutoAddPolicy
+
+
+class Connect:
+    """Set of connection methods (functions) for various protocols.
+    """
+    @staticmethod
+    # pylint: disable=W0718
+    def ssh_commands(
+        commands: (str, list),
+        hostname: str,
+        username: str,
+        password: str,
+        p_enable: (str, type(None)) = None,
+        port: int = 22,
+        wait: float = 0.5,
+        logger_alias: str = inspect.stack()[0].function
+        ) -> str:
+        """Handling SSH command executing.
+
+        Args:
+            commands (str, list): commands for executing.
+            hostname (str): remote hostname or ip address.
+            username (str): remote host username.
+            password (str): remote host password.
+            p_enable (str, None): enable mode password. Defaults to remote host password.
+            port (int, optional): remote host connection port. Defaults to 22.
+            wait (float): delay in seconds between commands. Defaults to 0.5.
+            logger_alias (str, optional): sublogger name. Defaults to function or method name.
+
+        Returns:
+            str: terminal response or 'ERROR'.
+        """
+        local_logger = logging.getLogger(logger_alias)
+        if Do.args_valid(locals(), Connect.ssh_commands.__annotations__):
+            if isinstance(commands, str):
+                commands = [commands]
+            if p_enable is None:
+                p_enable = password
+
+            client = SSHClient()
+            client.set_missing_host_key_policy(AutoAddPolicy())
+            local_logger.debug(msg=''
+                + '\n' + 'host: ' + hostname + ':' + str(port)
+                + '\n' + 'user: ' + username
+                + '\n' + 'pass: ' + password
+                + '\n' + 'p_en: ' + p_enable
+                + '\n' + 'commands: '
+                + '\n' + '\n  '.join(commands)
+                )
+            try:
+                client.connect(hostname=hostname, username=username, password=password, port=port)
+                chan = client.invoke_shell()
+                data = b''
+
+                for command in commands:
+                    while not chan.send_ready():
+                        sleep(wait)
+                    sleep(wait)
+                    chan.send(command + '\n')
+
+                    while not chan.recv_ready():
+                        sleep(wait)
+                    sleep(wait)
+                    resp = chan.recv(8388608)
+                    #print(resp.decode('utf-8'))
+
+                    if command == 'enable':
+                        chan.send(p_enable + '\n')
+
+                    data += resp
+
+                client.close()
+                return data.decode('utf-8')
+            except Exception as error:
+                local_logger.debug(msg='error: ' + '\n' + str(error))
+                return 'ERROR'
+
+
+class Cisco(Connect):
+    """Set of management methods (functions) for Cisco devices.
+    """
+    def __init__(self,
+        host: str,
+        user: str,
+        pswd: str,
+        p_en: (str, type(None)) = None,
+        port: int = 22,
+        wait: float = 0.05
+        ) -> None:
+        self._host = host
+        self._user = user
+        self._pswd = pswd
+        self._p_en = p_en
+        self._port = port
+        self._wait = wait
+        if self._p_en is None:
+            self._p_en = self._pswd
+
+    def interface_status(self,
+        name: str,
+        logger_alias: str = inspect.stack()[0].function
+        ) -> str:
+        """Get interface status.
+
+        Args:
+            name (str): interface name, example: 'gigabitEthernet 1/0/24'.
+            logger_alias (str, optional): sublogger name. Defaults to function or method name.
+
+        Raises:
+            ValueError: _description_
+
+        Returns:
+            str: _description_
+        """
+        local_logger = logging.getLogger(logger_alias)
+        if Do.args_valid(locals(), Cisco.interface_status.__annotations__):
+            commands = ['show interface ' + name + ' status']
+
+            response = self.ssh_commands(
+                commands=commands,
+                hostname=self._host,
+                username=self._user,
+                password=self._pswd,
+                p_enable=self._p_en,
+                port=self._port,
+                wait=self._wait
+                )
+            local_logger.debug(msg=""
+                    + "\n" + self._host + " response: "
+                    + "\n" + response
+                    )
+            if re.search(".*disabled.*", response, ):
+                return 'disabled'
+            elif re.search(".*notconnect.*", response, ):
+                return 'notconnect'
+            elif re.search(".*connect.*", response):
+                return 'connect'
+            else:
+                raise ValueError("port status unknown")
+
+    def interfaces_enable(self,
+        names: (str, list),
+        logger_alias: str = inspect.stack()[0].function
+        ) -> None:
+        """Enable defined interfaces.
+
+        Args:
+            names (str, list): interface name list, example: ['Gi0/1','Gi0/2'].
+            logger_alias (str, optional): sublogger name. Defaults to function or method name.
+
+        Returns:
+            None.
+        """
+        local_logger = logging.getLogger(logger_alias)
+        if Do.args_valid(locals(), Cisco.interfaces_enable.__annotations__):
+            if isinstance(names, str):
+                names = [names]
+            interfaces = []
+            for name in names:
+                interfaces.append('interface ' + name)
+                interfaces.append('no shutdown')
+
+            commands = ['enable', 'configure terminal'] + interfaces + ['end','write','exit']
+
+            response = self.ssh_commands(
+                commands=commands,
+                hostname=self._host,
+                username=self._user,
+                password=self._pswd,
+                p_enable=self._p_en,
+                port=self._port,
+                wait=self._wait
+                )
+            local_logger.debug(msg=""
+                + "\n" + self._host + " response: "
+                + "\n" + response
+                )
+            return None
+
+    def interfaces_disable(self,
+        names: (str, list),
+        logger_alias: str = inspect.stack()[0].function
+        ) -> None:
+        """Disable defined interfaces.
+
+        Args:
+            names (str, list): interface name list, example: ['Gi0/1','Gi0/2'].
+            logger_alias (str, optional): sublogger name. Defaults to function or method name.
+
+        Returns:
+            None.
+        """
+        local_logger = logging.getLogger(logger_alias)
+        if Do.args_valid(locals(), Cisco.interfaces_disable.__annotations__):
+            if isinstance(names, str):
+                names = [names]
+            interfaces = []
+            for name in names:
+                interfaces.append('interface ' + name)
+                interfaces.append('shutdown')
+
+            commands = ['enable', 'configure terminal'] + interfaces + ['end','write','exit']
+
+            response = self.ssh_commands(
+                commands=commands,
+                hostname=self._host,
+                username=self._user,
+                password=self._pswd,
+                p_enable=self._p_en,
+                port=self._port,
+                wait=self._wait
+                )
+            local_logger.debug(msg=""
+                + "\n" + self._host + " response: "
+                + "\n" + response
+                )
+            return None
+
+
+class Do():
+    """Set of various methods (functions) for routine.
+    """
+    @staticmethod
+    def args_valid(arguments: dict, annotations: dict) -> bool:
+        """Arguments type validating by annotations.
+
+        Args:
+            arguments (dict): 'locals()' immediately after starting the function.
+            annotations (dict): function.name.__annotations__.
+
+        Raises:
+            TypeError: type of argument is not equal type in annotation.
+
+        Returns:
+            bool: True if argument types are valid.
+        """
+        for var_name, var_type in annotations.items():
+            if not var_name == 'return':
+                if not isinstance(arguments[var_name], var_type):
+                    raise TypeError(""
+                        + "type of '"
+                        + var_name
+                        + "' = "
+                        + str(arguments[var_name])
+                        + " is not "
+                        + str(var_type)
+                        )
+        return True
+
+    @staticmethod
+    def ping(host: str) -> bool:
+        """Send ICMP echo request.
+
+        Args:
+            host (str): ip address or hostname.
+
+        Returns:
+            bool: True - host replied, False - host didn't respond
+        """
+        if platform.startswith('linux') or platform.startswith('darwin'):
+            process = ['ping', host, '-c', '1']
+        elif platform.startswith('win32'):
+            process = ['ping', host, '-n', '1', '>>', 'NUL']
+
+        with Popen(process, stdout=PIPE, stderr=STDOUT) as proc:
+            proc.communicate()
+        if proc.returncode == 0:
+            return True
+        return False
+
+
+if __name__ == "__main__":
+    time_start = datetime.datetime.now()
+
+    if 'argparse' in modules:
+        args = ArgumentParser(
+            prog='cisco-port-failover',
+            description='Cisco ports switching if the target is unreachable.',
+            epilog='Dependencies: '
+                '- Python 3 (tested version 3.9.5), '
+                '- Python 3 modules: paramiko '
+            )
+        args.add_argument('--host', type=str, required=True,
+                        help='cisco host address')
+        args.add_argument('--port', type=int, default=22, required=False,
+                        help='cisco ssh port')
+        args.add_argument('--user', type=str, default='cisco', required=False,
+                        help='cisco ssh username')
+        args.add_argument('--pass', type=str, default='cisco', required=False,
+                        help='cisco ssh password')
+        args.add_argument('--p_en', type=str, default=None, required=False,
+                        help='cisco enable mode password')
+        args.add_argument('--check', action='append', default=[], required=False,
+                        help='ping target host')
+        args.add_argument('--iface', action='append', default=[], required=False,
+                        help='cisco target interface')
+        args.add_argument('--wait', type=float, default=0.05, required=False,
+                        help='delay in seconds between commands')
+        args.add_argument('--log_root', type=str, default=path.dirname(path.realpath(__file__)),
+                        required=False,
+                        help='path to log directory')
+        args.add_argument('--log_level', type=str, default='INFO', required=False,
+                        help='DEBUG, INFO, WARNING, ERROR, CRITICAL')
+        args = vars(args.parse_args())
+
+    log_root = args['log_root']
+    log_level = args['log_level']
+
+    logging.basicConfig(
+        format='%(asctime)s %(levelname)s: %(name)s: %(message)s',
+        datefmt='%Y-%m-%d_%H.%M.%S',
+        handlers=[
+            logging.FileHandler(
+                filename=log_root + sep + path.splitext(path.basename(__file__))[0] + '.log',
+                mode='a'
+                ),
+            logging.StreamHandler()
+            ],
+        level=log_level
+        )
+    logging.getLogger("paramiko").setLevel(logging.WARNING)
+
+    device = Cisco(
+        host=args['host'],
+        user=args['user'],
+        pswd=args['pass'],
+        p_en=args['p_en'],
+        port=args['port'],
+        wait=args['wait']
+        )
+    for address in args['check']:
+        if Do.ping(host=address):
+            break
+    else:
+        iface_states = {'old': {}, 'new': {}}
+        iface_active_old_index = -1
+
+        # get source ports states (~2sec)
+        for iface in args['iface']:
+            iface_states['old'][iface] = device.interface_status(iface)
+            if iface_states['old'][iface] != 'disabled':
+                iface_active_old_index = args['iface'].index(iface)
+
+        # choice new active port
+        iface_active_new_index = iface_active_old_index + 1
+        if iface_active_new_index >= len(args['iface']):
+            iface_active_new_index = 0
+
+        # set ports new states (~4sec)
+        device.interfaces_disable(args['iface'])
+        device.interfaces_enable(args['iface'][iface_active_new_index])
+
+        # get current ports states (~2sec)
+        for iface in args['iface']:
+            iface_states['new'][iface] = device.interface_status(iface)
+
+        logging.info(msg=iface_states)
+
+    time_execute = datetime.datetime.now() - time_start
+    logging.info(msg='execution time is ' + str(time_execute) + '. Exit.')