The Death of Manual MAC Management

I was on a call with a Director of Security last month who was incredibly proud of their "Zero Trust" initiative. They had spent $500k on Cisco ISE licenses and hardware. But when I asked to see their operational workflow, he pointed at a spreadsheet.

"Every morning," he said, "our junior engineer takes the daily inventory export from our MDM and manually enters the new MAC addresses into the ISE Identity Groups."

My heart sank. That isn't Zero Trust. That's just a data-entry job with a very expensive security appliance.

At Technoxi, we have a saying: If you do it twice, script it. If you do it three times, automate it.

ModernCyber and other "high-level" partners love to show you slides of automation. I’m going to show you the actual Python and Ansible blueprint we use to turn ISE from a manual burden into an automated identity engine.

The Core Concept: The Identity Lifecycle

In a production environment, an endpoint (a laptop, a printer, an IoT camera) isn't static. It has a lifecycle:

1. Provisioning: The device is purchased and entered into your inventory.
2. Onboarding: The device connects to the network for the first time.
3. Validation: The device is profiled and its security posture is checked.
4. Maintenance: The device's SGT (Scalable Group Tag) might change based on its behavior.
5. Retirement: The device is decommissioned and should be removed from the security policy.

If you’re doing this manually, you’re always behind. Your security policy is always "stale."

Scaling with the ISE ERS API

The External RESTful Services (ERS) API is the secret weapon of the Cisco ISE powerhouse. It allows you to bypass the GUI entirely. Below is a more robust version of the "Identity Injection" logic we use.

Unlike a simple snippet, this includes the error handling and logging necessary for a production script.

import requests
from requests.auth import HTTPBasicAuth
import json
import logging

# Setup Production Logging
logging.basicConfig(level=logging.INFO, format='%(asctime)s - %(levelname)s - %(message)s')
logger = logging.getLogger(__name__)

class ISEAutomation:
    def __init__(self, host, user, password):
        self.base_url = f"https://{host}:9060/ers/config"
        self.auth = HTTPBasicAuth(user, password)
        self.headers = {
            "Content-Type": "application/json",
            "Accept": "application/json"
        }

    def sync_endpoint_to_group(self, mac_address, group_name):
        """
        Ensures an endpoint is in the correct Identity Group.
        If it doesn't exist, create it. If it does, update the group.
        """
        # First, find the group ID by name
        group_id = self._get_group_id(group_name)
        if not group_id:
            logger.error(f"Identity Group {group_name} not found in ISE.")
            return

        url = f"{self.base_url}/endpoint"
        payload = {
            "ERSEndpoint": {
                "name": mac_address,
                "mac": mac_address,
                "groupId": group_id,
                "staticProfileAssignment": True,
                "description": "Automated sync from Technoxi Identity Engine"
            }
        }

        try:
            response = requests.post(url, auth=self.auth, data=json.dumps(payload), headers=self.headers, verify=False)
            
            if response.status_code == 201:
                logger.info(f"Successfully PROVISIONED {mac_address} into {group_name}")
            elif response.status_code == 400 and "already exists" in response.text:
                # Logic for updating existing endpoint would go here (PUT request)
                logger.info(f"Endpoint {mac_address} already exists. Moving to Update logic...")
                self._update_endpoint(mac_address, group_id)
            else:
                logger.error(f"API Error: {response.status_code} - {response.text}")
        
        except requests.exceptions.RequestException as e:
            logger.critical(f"Connection to ISE failed: {e}")

    def _get_group_id(self, name):
        # Internal helper to map names to IDs
        # In a real environment, we cache these to avoid excessive API calls
        return "29ca2b80-8c00-11e3-857e-005056bc4484" # Representative ID

    def _update_endpoint(self, mac, group_id):
        # Update logic implementation...
        pass

# Example: Automating the IoT VLAN
# engine = ISEAutomation("ise.internal.inc", "api_user", "secure_pass")
# engine.sync_endpoint_to_group("00:50:56:AB:CD:EF", "Global_IoT_Devices")

Ansible: Standardizing the Policy Set

Python is great for identity data, but Ansible is the king of policy configuration.

When we work with a customer, we don't just "set up ISE." We create a Git repository for their ISE policy. If you want to change a rule in your "Security_Policy_Set," you don't log into a GUI. You submit a Pull Request.

This is "GitOps for Security." It provides:

1. Auditability: You know exactly who changed a rule and when.
2. Consistency: Your Production, Staging, and Labs nodes are identical.
3. Speed: Rolling back a bad policy takes seconds (git revert) instead of hours of clicking.

The Technoxi Ansible Workflow:

We use the cisco.ise collection. A typical playbook to ensure your SGTs are standardized looks like this:

- name: Ensure Corporate SGTs are standardized
  cisco.ise.sgt:
    ise_hostname: "{{ ise_host }}"
    ise_username: "{{ ise_user }}"
    ise_password: "{{ ise_password }}"
    ise_verify: no
    state: present
    name: "{{ item.name }}"
    description: "{{ item.description }}"
    value: "{{ item.value }}"
  loop:
    - { name: 'Contractor_Untrusted', value: 15, description: 'Restricted access for external vendors' }
    - { name: 'Finance_Critical', value: 20, description: 'High-security zone for payroll apps' }

Why "Mentored Install" (MINT) is the only way

I’m giving you this code because I know that reading a snippet is one thing, but deploying it in a production environment with 10,000 users is another.

Most vendors will offer to "Professional Services" this for you. They’ll build a custom script, hand you the password, and wish you luck. That is a dangerous model.

When that script breaks in six months (and it will, as APIs evolve), you’re stuck.

Our Cisco MINT Mentored Install program is different. We don't just "deliver" a solution. We act as your automation mentors, ensuring your team owns the code.

• We sit with your network team and teach them basic Python.
• We show them how to use Postman to explore the ISE API.
• We build your GitOps workflow with you, using your actual security policy.

By the end of a Technoxi MINT Engagement, you don't just have an automated network; you have a team of NetDevOps Engineers who can maintain and grow it themselves.

For the Cisco Sales Team: If you want to ensure your customer actually adopts the advanced features of ISE and doesn't just let the license sit idle, MINT is the answer. Use SKU MINT-SECURITY-TNX in CCW. It simplifies your BoM and guarantees a successful, automated outcome for your customer.

Watch our ISE Automation Demo to see this lifecycle in action or Calculate your ROI on moving from manual to automated operations and see why MINT is the standard for partner-led success.

Are you ready to stop clicking?

The transition from "Engineer" to "NetDevOps Engineer" is the biggest hurdle in modern networking. What’s the one thing holding your team back from automating your security policy today? Let's talk about the blockers in the comments.

Tom Alexander CTO, Technoxi Ex-Cisco TAC | DevNet Associate