[LINUX – Ubuntu] Set Up a Tailscale Exit Node and Subnet Router in Ubuntu Linux

In today’s interconnected world, secure remote access to networks and the ability to route traffic through specific geographic locations has become essential for businesses and developers alike. Tailscale provides an elegant solution by creating a secure mesh VPN that simplifies network connectivity across devices and locations.

Setting up a Tailscale exit node allows you to route your internet traffic through a specific server, providing benefits like accessing geo-restricted content, enhanced privacy, and consistent IP addresses. Meanwhile, a subnet router enables you to access resources on a remote network through your Tailscale connection. This tutorial will guide you through configuring both features on an Ubuntu server.

Prerequisites

Before we begin, ensure you have the following:

• An Ubuntu 24.04 LTS VPS with at least 1GB RAM and 1 CPU core
• Root or sudo access to the server
• A Tailscale account (free tier available)
• Basic familiarity with Linux command line
• SSH access to your VPS

For this tutorial, we’ll assume you’re using a fresh Ubuntu 24.04 LTS installation. The commands provided work for both root and non-root users with sudo privileges.

Step-by-Step Tutorial

Step 1: Update System Packages

First, ensure your system is up to date

sudo apt update && sudo apt upgrade -y

Step 2: Install Tailscale

Install Tailscale using the official installation script

curl -fsSL https://tailscale.com/install.sh

This script automatically detects your distribution and installs the appropriate Tailscale package. For Ubuntu 24.04, it will install the latest stable version from Tailscale’s APT repository.

Step 3: Authenticate Tailscale

Start Tailscale and authenticate your device.

sudo tailscale up

This command will generate an authentication URL. Copy and paste it into your browser to authenticate with your Tailscale account. Once authenticated, your VPS will appear in your Tailscale admin console.

Step 4: Enable IP Forwarding

For both exit node and subnet routing functionality, enable IP forwarding.

echo 'net.ipv4.ip_forward = 1' | sudo tee -a /etc/sysctl.conf
echo 'net.ipv6.conf.all.forwarding = 1' | sudo tee -a /etc/sysctl.conf
sudo sysctl -p

Verify the settings are applied

sudo sysctl net.ipv4.ip_forward net.ipv6.conf.all.forwarding

Step 5: Configure Exit Node

Enable your VPS as an exit node by running

sudo tailscale up --advertise-exit-node

This command configures your VPS to advertise itself as an exit node to other devices in your tailnet (Tailscale network).

Step 6: Configure Subnet Router (Optional)

If you want to route traffic to specific subnets through your VPS, configure subnet routing. First, identify the subnets you want to advertise.

ip route | grep -E "(eth0|ens|enp)"
ip -6 route | grep -E "(eth0|ens|enp)"

Then advertise the subnets (replace with your actual subnet ranges)

sudo tailscale up --advertise-exit-node --advertise-routes=192.168.1.0/24,10.0.0.0/24

Step 7: Approve Routes in Admin Console

Navigate to your Tailscale Admin Console and

• Locate your VPS in the machines list
• Click the three dots menu next to your VPS
• Select “Edit route settings”
• Approve the exit node and/or subnet routes
• Optionally, disable key expiry for unattended operation

Step 8: Configure Firewall

If using UFW (Ubuntu’s default firewall), configure it to allow Tailscale traffic.

sudo ufw allow in on tailscale0

sudo ufw allow 41641/udp

For iptables users, ensure forwarding rules are properly configured

sudo iptables -A FORWARD -i tailscale0 -j ACCEPT

sudo iptables -A FORWARD -o tailscale0 -j ACCEPT

Step 9: Test Configuration

From another device in your tailnet, test the exit node functionality:

# Check your current IP
curl ifconfig.me

# Enable exit node on client device
tailscale up --exit-node=YOUR_VPS_TAILSCALE_IP 

#Verify IP has changed
curl ifconfig.me

For subnet routing, test connectivity to resources within the advertised subnets using their private IP addresses.

Reference

Set Up a Tailscale Exit Node and Subnet Router on an Ubuntu 24.04 VPS – Onidel Cloud