Configure Site to Site VPN on Cisco ASA

Welcome to my channel , in this  video i will configure site to site vpn on Cisco ASA . i will show you the steps to set up a secure and reliable VPN connection between two Cisco Adaptive Security Appliances (ASAs).

Before we dive into the technical aspects, let’s take a moment to understand the importance of site-to-site VPNs in today’s interconnected world. As businesses expand globally, secure communication between different locations becomes paramount. Whether you’re connecting remote offices, data centers, or branch networks, a site-to-site VPN offers a robust solution to ensure data confidentiality, integrity, and availability.

Assumptions:

  • You have physical or remote access to the Cisco ASA device.
  • You have administrative access to the ASA via SSH, console cable, or ASDM (Adaptive Security Device Manager).

Step 1: Basic ASA Configuration

  1. Connect to the ASA using SSH or the console cable.
  2. Log in with your administrator credentials.

hostname ASA_NAME enable password YOUR_ENABLE_PASSWORD passwd YOUR_CONSOLE_PASSWORD interface GigabitEthernet0/0 nameif outside security-level 0 ip address YOUR_OUTSIDE_IP 255.255.255.0 no shutdown exit interface GigabitEthernet0/1 nameif inside security-level 100 ip address YOUR_INSIDE_IP 255.255.255.0 no shutdown exit route outside 0.0.0.0 0.0.0.0 YOUR_GATEWAY_IP 1

  1. Replace ASA_NAME, YOUR_ENABLE_PASSWORD, YOUR_CONSOLE_PASSWORD, YOUR_OUTSIDE_IP, YOUR_INSIDE_IP, and YOUR_GATEWAY_IP with your specific values.

Step 2: Define ISAKMP Policy

  1. Configure the ISAKMP (Internet Security Association and Key Management Protocol) policy to specify the encryption and authentication parameters for the VPN.

crypto isakmp policy 10 authentication pre-share encryption aes-256 hash sha group 2 lifetime 86400

Step 3: Create a Pre-shared Key

  1. Define a pre-shared key that will be used to authenticate the remote VPN peer.

crypto isakmp key YOUR_PRESHARED_KEY address REMOTE_PEER_IP

Replace YOUR_PRESHARED_KEY with your chosen pre-shared key and REMOTE_PEER_IP with the IP address of the remote VPN peer.

Step 4: Create a Crypto Map

  1. Create a crypto map that defines the remote peer’s IP, transform sets, and access control list (ACL) for traffic to be encrypted.

crypto map MY_CRYPTO_MAP 10 match address VPN_ACL crypto map MY_CRYPTO_MAP 10 set peer REMOTE_PEER_IP crypto map MY_CRYPTO_MAP 10 set transform-set MY_TRANSFORM_SET

Replace MY_CRYPTO_MAP, VPN_ACL, REMOTE_PEER_IP, and MY_TRANSFORM_SET with your desired values.

Step 5: Create an Access Control List (ACL)

  1. Define an access control list (ACL) that identifies which traffic should be encrypted and sent over the VPN.

access-list VPN_ACL extended permit ip LOCAL_NETWORK SUBNET_MASK any

Replace LOCAL_NETWORK and SUBNET_MASK with your local network’s details.

Step 6: Apply Crypto Map to an Interface

  1. Apply the crypto map to the ASA’s outside interface.

crypto map MY_CRYPTO_MAP interface outside

Step 7: Save the Configuration

  1. Save the configuration changes.

write memory

Step 8: Verify the VPN

  1. Check the VPN status using the following command:

show crypto isakmp sa show crypto ipsec sa

These commands will display information about the IKE and IPsec tunnels.

That’s it! You’ve configured a Site-to-Site VPN on a Cisco ASA. Remember to adjust the configuration to match your specific network topology and security requirements. Additionally, ensure that the remote peer’s configuration matches the parameters you’ve configured here for successful VPN establishment.

Install and Config Cisco ASA on GNS3

Hello, today we will install GNS3 with you and then we will install CISCO ASA on it. I will also explain how we can connect to Cisco ASA with ASDM.

Let’s start.

Step 1: Obtain Cisco ASA Image

You’ll need a Cisco ASA image file to run it in GNS3. You can acquire this image from legal and legitimate sources, such as Cisco’s official website, or if you have a Cisco ASA device, you may be able to extract it. Make sure you have the proper licensing to use the image.

Step 2: Install GNS3

If you haven’t already, download and install GNS3 on your computer from the official website (https://www.gns3.com/). Follow the installation instructions for your specific operating system.

Step 3: GNS3 Initial Setup

  1. Launch GNS3 and complete the initial setup wizard. This typically includes configuring preferences like where to store your projects and images.
  2. Make sure you have the GNS3 VM (Virtual Machine) configured and running. You can download the GNS3 VM from the GNS3 website and follow the installation instructions provided there.

Step 4: Add Cisco ASA to GNS3

  1. In GNS3, go to “Edit” > “Preferences.”
  2. In the Preferences window, click on “QEMU VMs” on the left sidebar.
  3. Click the “New” button to add a new virtual machine.
  4. Provide a name for the virtual machine (e.g., “Cisco ASA”).
  5. In the “Type” dropdown menu, select “ASA” for Cisco ASA.
  6. In the “QEMU binary” section, browse and select the QEMU binary executable. This binary should be located in your GNS3 VM.
  7. Set the RAM and CPU settings based on your system resources and requirements.
  8. Click “Next” and follow the on-screen instructions to complete the virtual machine setup.

Step 5: Add ASA Image to GNS3

  1. In GNS3, go to “Edit” > “Preferences” again.
  2. In the Preferences window, click on “QEMU” on the left sidebar.
  3. Click the “QEMU VMs” tab.
  4. Select the “Cisco ASA” virtual machine you created earlier.
  5. In the “QEMU Options” section, click the “Browse” button next to “QEMU image” and select the Cisco ASA image file you obtained.

Step 6: Configure Cisco ASA in GNS3

  1. Drag and drop the Cisco ASA device from the GNS3 device list onto your GNS3 workspace.
  2. Right-click on the ASA device and choose “Start.”
  3. Right-click again and select “Console” to open the console window for the ASA.
  4. Configure the ASA as needed using the command-line interface (CLI). This includes setting up interfaces, IP addresses, access control policies, and any other configurations you require.
  5. Save your configurations to ensure they persist across sessions.

With these steps, you should have a Cisco ASA running in GNS3, ready for configuration and testing in your simulated network environment. Remember to follow proper licensing and usage guidelines when using Cisco ASA images.