IKE Authentication Made Simple: Secure Cisco VPN with IPsec & Pre-Shared Keys 🔐

Router(config)# crypto isakmp policy 10
🔹 Starts defining ISAKMP policy #10. Lower numbers have higher priority.

Router(config-isakmp)# encryption aes
🔹 Sets AES encryption for the IKE Phase 1 tunnel, ensuring confidentiality.

Router(config-isakmp)# hash sha256
🔹 Specifies SHA-256 for integrity checking of the ISAKMP messages.

Router(config-isakmp)# authentication pre-share
🔹 Defines authentication method. Pre-shared keys are simpler and common in site-to-site VPNs.

Router(config-isakmp)# group 2
🔹 Sets Diffie-Hellman group 2 (1024-bit). This helps exchange keys securely.

Router(config-isakmp)# lifetime 86400
🔹 Sets the SA (Security Association) lifetime to 24 hours (in seconds).

Router(config)# crypto isakmp key YOUR_SECRET_KEY address x.x.x.x
🔹 Defines the shared secret (pre-shared key) to authenticate the peer at the specified IP.

🔹'Router# show crypto isakmp policy' : Displays all configured ISAKMP policies.

🔹 'Router# show crypto isakmp sa': Shows the current Security Associations (active IKE Phase 1 sessions).

#Cisco #IKE #IPSec #VPN #NetworkSecurity #coresahnetworks #CiscoVPN #IKEAuthentication #CiscoConfiguration #CyberSecurity #RouterConfiguration #PreSharedKey #CCNA #CCNP #Encryption #NetworkEngineer