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npx versuz@latest install mukul975-anthropic-cybersecurity-skills-skills-implementing-network-access-control-with-cisco-isegit clone https://github.com/mukul975/Anthropic-Cybersecurity-Skills.gitcp Anthropic-Cybersecurity-Skills/SKILL.MD ~/.claude/skills/mukul975-anthropic-cybersecurity-skills-skills-implementing-network-access-control-with-cisco-ise/SKILL.md--- name: implementing-network-access-control-with-cisco-ise description: Deploy Cisco Identity Services Engine for 802.1X wired and wireless authentication, MAC Authentication Bypass, posture assessment, and dynamic VLAN assignment for network access control. domain: cybersecurity subdomain: network-security tags: - cisco-ise - 802.1x - nac - radius - network-access-control - posture-assessment - mab - dynamic-vlan - eap-tls version: '1.0' author: mahipal license: Apache-2.0 nist_csf: - PR.IR-01 - DE.CM-01 - ID.AM-03 - PR.DS-02 --- # Implementing Network Access Control with Cisco ISE ## Overview Cisco Identity Services Engine (ISE) provides centralized network access control through 802.1X authentication, MAC Authentication Bypass (MAB), posture assessment, and guest access management. ISE acts as a RADIUS policy server that evaluates authentication requests from network devices (switches, wireless controllers) and returns authorization policies including VLAN assignments, downloadable ACLs (dACLs), and Security Group Tags (SGTs). This skill covers deploying ISE for enterprise wired 802.1X authentication with Active Directory integration, MAB fallback, posture compliance enforcement, and TrustSec segmentation. ## When to Use - When deploying or configuring implementing network access control with cisco ise capabilities in your environment - When establishing security controls aligned to compliance requirements - When building or improving security architecture for this domain - When conducting security assessments that require this implementation ## Prerequisites - Cisco ISE 3.1+ appliance or virtual machine (16 CPU cores, 64GB RAM minimum for production) - Cisco switches with 802.1X support (Catalyst 9000 series recommended) - Active Directory domain with user and computer accounts - PKI infrastructure for EAP-TLS certificate-based authentication - DNS and NTP configured consistently across ISE nodes and network devices - Supplicant software on endpoints (Windows native, AnyConnect NAM, or SecureW2) ## Core Concepts ### 802.1X Architecture The 802.1X framework involves three components: | Component | Role | Example | |-----------|------|---------| | **Supplicant** | Client requesting network access | Windows 802.1X client, AnyConnect NAM | | **Authenticator** | Network device controlling port access | Cisco Catalyst switch | | **Authentication Server** | Policy decision engine | Cisco ISE (RADIUS) | ### Authentication Flow ``` 1. Endpoint connects to switch port 2. Switch sends EAP-Request/Identity to endpoint 3. Endpoint responds with EAP-Response/Identity 4. Switch forwards credentials to ISE via RADIUS Access-Request 5. ISE authenticates against AD/LDAP/internal store 6. ISE evaluates authorization policy 7. ISE returns RADIUS Access-Accept with attributes (VLAN, dACL, SGT) 8. Switch enforces authorization on the port ``` ### Authentication Methods | Method | Use Case | Security Level | |--------|----------|---------------| | EAP-TLS | Certificate-based, highest security | High | | PEAP-MSCHAPv2 | Username/password via AD | Medium | | EAP-FAST | Cisco proprietary, fast reauthentication | Medium | | MAB | Non-802.1X devices (printers, IP phones) | Low | ## Workflow ### Step 1: Configure ISE for Active Directory Integration Navigate to **Administration > Identity Management > External Identity Sources > Active Directory**: 1. Add AD join point with domain name (e.g., `corp.example.com`) 2. Provide domain admin credentials for ISE machine account 3. Join ISE to the domain 4. Select AD groups for authorization policies: - `Domain Users` - Standard employee access - `Domain Computers` - Machine authentication - `IT-Admins` - Privileged access - `BYOD-Users` - Personal device access ### Step 2: Configure Network Devices in ISE Navigate to **Administration > Network Resources > Network Devices**: ``` Name: SW-ACCESS-01 IP Address: 10.0.1.1/32 RADIUS Shared Secret: C0mpl3x$3cretKey! SNMP Settings: v2c, community string Device Type: Cisco Switches Location: Building-A-Floor-1 ``` Create a Network Device Group hierarchy: ``` Device Type: ├── Cisco Switches │ ├── Access Layer │ └── Distribution Layer └── Wireless Controllers Location: ├── Building-A └── Building-B ``` ### Step 3: Configure Switch for 802.1X Apply this configuration to the access switch: ``` ! Enable AAA aaa new-model aaa authentication dot1x default group radius aaa authorization network default group radius aaa accounting dot1x default start-stop group radius aaa accounting update newinfo periodic 2880 ! Configure RADIUS server radius server ISE-PRIMARY address ipv4 10.0.5.10 auth-port 1812 acct-port 1813 key 0 C0mpl3x$3cretKey! automate-tester username radius-test probe-on radius server ISE-SECONDARY address ipv4 10.0.5.11 auth-port 1812 acct-port 1813 key 0 C0mpl3x$3cretKey! automate-tester username radius-test probe-on aaa group server radius ISE-GROUP server name ISE-PRIMARY server name ISE-SECONDARY deadtime 15 ip radius source-interface Loopback0 ! Enable 802.1X globally dot1x system-auth-control ! Enable RADIUS CoA (Change of Authorization) aaa server radius dynamic-author client 10.0.5.10 server-key C0mpl3x$3cretKey! client 10.0.5.11 server-key C0mpl3x$3cretKey! ! Enable device tracking for IP-to-MAC mapping device-tracking tracking auto-source ! Configure access port template interface range GigabitEthernet1/0/1-48 description 802.1X Access Port switchport mode access switchport access vlan 100 ! Authentication settings authentication host-mode multi-auth authentication order dot1x mab authentication priority dot1x mab authentication port-control auto authentication periodic authentication timer reauthenticate server authentication timer inactivity server dynamic authentication violation restrict ! 802.1X settings dot1x pae authenticator dot1x timeout tx-period 10 dot1x max-reauth-req 2 ! MAB fallback mab ! Enable spanning-tree portfast (required for timely auth) spanning-tree portfast ! Apply pre-auth ACL ip access-group PRE-AUTH-ACL in ! Pre-authentication ACL (allow DHCP, DNS, ISE portal) ip access-list extended PRE-AUTH-ACL permit udp any any eq 67 permit udp any any eq 68 permit udp any any eq 53 permit tcp any host 10.0.5.10 eq 8443 permit tcp any host 10.0.5.11 eq 8443 deny ip any any ``` ### Step 4: Configure ISE Authentication Policy Navigate to **Policy > Policy Sets**: **Authentication Policy:** | Rule Name | Condition | Allowed Protocols | Identity Source | |-----------|-----------|-------------------|-----------------| | Dot1X-EAP-TLS | Radius:EAP-Type EQUALS EAP-TLS | EAP-TLS | AD with Certificate | | Dot1X-PEAP | Radius:EAP-Type EQUALS PEAP | PEAP-MSCHAPv2 | Active Directory | | MAB | Radius:Service-Type EQUALS Call-Check | MAB Lookup | Internal Endpoints | | Default | Default | Default | Deny Access | ### Step 5: Configure ISE Authorization Policy **Authorization Policy:** | Rule Name | Condition | Authorization Profile | |-----------|-----------|----------------------| | IT-Admin-Wired | AD:Group EQUALS IT-Admins AND Dot1X | VLAN10-FullAccess | | Employee-Compliant | AD:Group EQUALS Domain Users AND Posture:Compliant | VLAN100-Corporate | | Employee-NonCompliant | AD:Group EQUALS Domain Users AND Posture:NonCompliant | VLAN200-Remediation | | Printer-MAB | EndpointIdentityGroup EQUALS Printers | VLAN150-Printers | | IP-Phone-MAB | EndpointIdentityGroup EQUALS IP-Phones | VLAN50-Voice | | BYOD-Onboarding | AD:Group EQUALS BYOD-Users AND !Registered | BYOD-Portal-Redirect | | Guest-Access | GuestEndpointGroup EQUALS GuestEndpoints | VLAN300-Guest | | Default | Default | DenyAccess | **Authorization Profiles:** ``` Profile: VLAN100-Corporate VLAN: 100 dACL: PERMIT_ALL SGT: Employees (0x0005) Reauthentication Timer: 28800 Profile: VLAN200-Remediation VLAN: 200 dACL: REMEDIATION-ACL (allow only remediation server access) Web Redirection: Posture Discovery Reauthentication Timer: 300 Profile: DenyAccess Access Type: ACCESS_REJECT ``` ### Step 6: Configure Posture Assessment Navigate to **Work Centers > Posture**: **Posture Conditions:** ``` - Windows Firewall Enabled (Registry check) - Antivirus Running and Updated (AV compound condition) - OS Patch Level Current (Windows Update check) - Disk Encryption Enabled (BitLocker check) ``` **Posture Requirements:** ``` Requirement: Corporate-Windows-Compliance OS: Windows All Conditions: Windows Firewall AND Antivirus AND OS Patches Remediation: Auto-remediate with AnyConnect ISE Posture Module ``` **Posture Policy:** ``` Rule: Windows-Endpoints Identity Group: Any OS: Windows All Requirement: Corporate-Windows-Compliance ``` ### Step 7: Configure TrustSec Segmentation Enable SGT-based segmentation: ``` ! On switch - enable CTS cts credentials id SW-ACCESS-01 password CtsP@ss cts role-based enforcement cts role-based sgt-map 10.0.100.0/24 sgt 5 ! Download SGT policy from ISE cts role-based permissions ``` ISE TrustSec Matrix (SGACL): | Source SGT | Destination SGT | Policy | |------------|----------------|--------| | Employees (5) | Servers (10) | Permit_HTTP_HTTPS | | Employees (5) | PCI_Zone (15) | Deny_All | | IT-Admins (3) | Servers (10) | Permit_All | | Guest (7) | Internet (99) | Permit_HTTP_HTTPS | | Guest (7) | Servers (10) | Deny_All | ## Troubleshooting ```bash # On switch - verify authentication status show authentication sessions show authentication sessions interface Gi1/0/1 details show dot1x all # Check RADIUS connectivity test aaa server radius ISE-PRIMARY username testuser password testpass # On ISE - check live logs # Navigate to Operations > RADIUS > Live Logs # Filter by MAC address or username # Review Authentication Details for failure reason # Common failure reasons: # 12514 - EAP-TLS handshake failed (certificate issue) # 22056 - Subject not found in identity store # 24408 - User not found in Active Directory # 24454 - User password expired ``` ## Best Practices - **Monitor Mode First** - Deploy in monitor mode (open authentication) before closed mode enforcement - **Low-Impact Mode** - Use `authentication open` with pre-auth dACLs for gradual rollout - **MAB Database** - Pre-populate endpoint database with known MAC addresses for printers, phones - **Profiling** - Enable ISE profiling to automatically classify endpoints by type - **CoA Support** - Ensure Change of Authorization is configured for dynamic policy updates - **High Availability** - Deploy ISE in a Primary/Secondary node pair with PAN failover - **Certificate Infrastructure** - Use machine certificates for EAP-TLS for strongest authentication ## References - [Cisco ISE Admin Guide 3.1](https://www.cisco.com/c/en/us/td/docs/security/ise/3-1/admin_guide/b_ise_admin_3_1.html) - [Cisco 802.1X Design Guide](https://www.cisco.com/c/en/us/support/docs/lan-switching/8021x/214843-guide-ieee-802-1x-deployment-with-cisco.html) - [CiscoLive ISE Deployment Guide 2025](https://www.ciscolive.com/c/dam/r/ciscolive/emea/docs/2025/pdf/BRKSEC-2660.pdf) - [Cisco ISE Wired 802.1X Configuration](https://www.networkcomputing.com/network-security/cisco-ise-wired-802-1x-configuration)