How to Set Up ZeroTier for Virtual Networking

What Is ZeroTier?

ZeroTier is a software-defined networking tool that creates virtual Ethernet networks spanning your Breezes, local machines, and cloud instances. It uses peer-to-peer encrypted connections and supports Layer 2 bridging, making it ideal for building private overlay networks.

Prerequisites

• A Breeze running Ubuntu 22.04 or later
• A ZeroTier account (free for up to 25 nodes)

Create a Network

Log in to my.zerotier.com and create a new network. Note the 16-character Network ID that is generated.

Install ZeroTier

curl -s https://install.zerotier.com | sudo bash

Join the Network

sudo zerotier-cli join <NETWORK_ID>

Authorize the node in the ZeroTier Central web console. Once authorized, verify connectivity:

sudo zerotier-cli listnetworks

Assign Static IPs

In ZeroTier Central, navigate to the network members list. You can assign managed IP addresses within your chosen subnet (e.g., 10.147.17.0/24) to each node for consistent addressing.

Enable Bridging

To bridge ZeroTier traffic to a physical LAN:

sudo zerotier-cli set <NETWORK_ID> allowGlobal=true
echo "net.ipv4.ip_forward = 1" | sudo tee -a /etc/sysctl.conf
sudo sysctl -p

Check the "Allow Ethernet Bridging" option for the node in ZeroTier Central. Add a managed route for the LAN subnet pointing to the bridge node.

Firewall Considerations

ZeroTier traffic uses UDP port 9993. Ensure your Breeze's firewall allows outbound UDP on that port. No inbound rules are needed since connections are initiated outward.