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Infrastructure Security and Services

Device Security on Cisco IOS XE

Control Plane Policing and Protection

  • Control Plane Policing (CoPP): Protects routers/switches from DoS attacks by managing control plane traffic through a separate interface (punt/inject). QoS rules are applied to control the rate of traffic, ensuring consistent performance.
  • Example Configuration: A QoS policy for Telnet traffic limits unwanted traffic while allowing trusted hosts unrestricted access.

Terminal Lines and Password Protection

  • Access Methods: Devices can be accessed through console ports (local), auxiliary ports (remote via modem), or virtual terminals (Telnet/SSH).
  • Password Types:
    • Type 0: Unencrypted, insecure.
    • Type 5: Stronger encryption (MD5), used with enable secret.
    • Type 7: Weak encryption, easily cracked.
    • Type 8/9: Secure passwords using modern hashing (PBKDF2, SCRYPT).

Configuring Local Password Authentication

  • Commands: Use password and login to enable basic password checks or configure username-based authentication with username and login local.

Privilege Levels & Role-Based Access Control (RBAC)

  • Privilege Levels:
    • 0: Basic commands.
    • 1 (User EXEC): Limited access.
    • 15 (Privileged EXEC): Full administrative control.

Configuring SSH

  • Basic Steps: Configure hostname, username, domain name, and generate RSA keys to enable SSH.

AAA (Authentication, Authorization, and Accounting)

  • TACACS+: Preferred for device access control, uses TCP port 49. Separates authentication, authorization, and accounting.
  • RADIUS: Preferred for network access, uses UDP, supports EAP for secure network authentication.

Configuring AAA

  • Example: Create AAA groups for TACACS+ servers, and enable login authentication using method lists (TACACS+, local, enable password).

Zone-Based Firewall (ZBFW)

  • Stateful Firewall: Inspects Layers 4-7, mitigating DDoS and improving network security at branch sites with built-in firewall capabilities.
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