PfSense L2TP Server & MikroTik Client Guide

by Jhon Lennon 44 views

Hey guys! Ever found yourself needing to connect your network, especially using a solid device like a MikroTik router, back to your main network through a pfSense firewall? If you're looking to establish a secure and reliable connection using the L2TP protocol, you've landed in the right spot. We're going to walk through how to get your pfSense box acting as an L2TP server and then connect a MikroTik router as a client. This is super handy for remote access, site-to-site VPNs, or just expanding your network's reach securely. Let's dive in and make this happen!

Understanding the Basics: L2TP, pfSense, and MikroTik

Before we jump into the nitty-gritty configuration, let's get a handle on what we're dealing with. L2TP (Layer 2 Tunneling Protocol) is a VPN protocol used to support VPNs or network roaming. It doesn't provide encryption on its own, which is why it's almost always paired with IPsec (Internet Protocol Security) for robust security. Think of L2TP as the tunnel builder, and IPsec as the armored truck that carries your data through that tunnel. This combination, often referred to as L2TP/IPsec, is a widely supported and secure way to establish VPN connections. Now, pfSense is a powerhouse open-source firewall and router software. It's incredibly flexible and offers a ton of features, including robust VPN capabilities. We'll be leveraging its built-in IPsec and L2TP server functionalities. On the other side, we have MikroTik, another fantastic company known for its powerful and versatile networking hardware and software (RouterOS). MikroTik devices are often used by network enthusiasts and professionals alike for their performance and configurability. Getting a MikroTik router to connect as an L2TP/IPsec client to your pfSense server is a common and highly effective scenario. This setup allows devices behind your MikroTik router to securely access resources on your pfSense network, or vice versa. It's all about creating a secure bridge between two networks over an untrusted network, like the internet. We'll cover the essential steps on both the pfSense server side and the MikroTik client side to ensure a smooth and successful connection. So, buckle up, and let's get this VPN tunnel up and running!

Configuring pfSense as an L2TP Server

Alright, let's get our pfSense box ready to accept those incoming L2TP connections. This is the core of our setup, so pay close attention here, guys. We'll be setting up both the IPsec tunnel and the L2TP server itself. First things first, make sure you have pfSense installed and accessible. You'll need administrative access to the web interface.

Step 1: Set up IPsec Tunnel

  • Navigate to VPN > IPsec. This is where all the magic happens for our secure tunnel.
  • Add P1 (Phase 1): Click on "Add P1" to create the first phase of our IPsec connection. This establishes the secure control channel.
    • Key Exchange version: Choose IKEv2 for better security and performance. If your MikroTik client is older, you might need to use IKEv1, but IKEv2 is preferred.
    • Internet Protocol: IPv4 is typical, but choose IPv6 if needed.
    • Interface: Select your WAN interface (the one facing the internet).
    • Remote Gateway: This is crucial. You'll leave this blank if you want to accept connections from any remote IP (dynamic clients). If you have a static IP for your MikroTik client, you can enter it here for added security (site-to-site).
    • Authentication Method: Choose Mutual PSK (Pre-Shared Key). This means both sides will use the same secret key.
    • My identifier: Usually My IP address.
    • Peer identifier: If you specified a Remote Gateway, you might set this to Peer IP address or Distinguished name. For dynamic clients, leave this as Any or Unknown.
    • Pre-Shared Key: Generate a strong, complex pre-shared key. This is like a secret password for your VPN. Do not use anything easy to guess! Keep this key safe; you'll need it on the MikroTik client.
    • Encryption Algorithm: Select strong algorithms. For encryption, AES (e.g., AES 256-GCM) is excellent. For hash, SHA256 or higher is recommended. For Diffie-Hellman group, choose a strong group like 14 or higher.
    • Lifetime: The default is usually fine (e.g., 28800 seconds).
    • NAT Traversal: Ensure this is enabled (Auto or Force). This is vital if either pfSense or the MikroTik client is behind NAT.
  • Save and Apply Changes.

Step 2: Add P2 (Phase 2) for L2TP/IPsec

Once P1 is saved, you'll see it in the list. Click the "Show Phase 2 Entries" button for your newly created P1 entry, then click "Add P2". This defines how the actual data traffic will be encrypted and routed.

  • Mode: Tunnel IPv4.
  • Local Network: This defines what your pfSense server considers its