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Connect private network to Internet

This guide covers how to connect a private network to the Internet using WARP Connector. In this example, we will create a WARP Connector for subnet 10.0.0.0/24 and install it on 10.0.0.1.

    flowchart LR
      subgraph subnet1[Subnet 10.0.0.0/24]
        device1["Device
        10.0.0.2"]-->router1["WARP Connector
        10.0.0.1"]
      end
      router1-->C((Cloudflare))-->I{Internet}

Prerequisites

1. Install a WARP Connector

To install WARP Connector on a host machine:

  1. In Zero Trust, go to Networks > Tunnels.

  2. Select Create a tunnel.

  3. For the tunnel type, select WARP Connector.

  4. You will be prompted to turn on Warp to Warp and Override local interface IP if they are currently turned off. These settings allow Cloudflare to assign a unique CGNAT IP to each WARP device and route traffic between them.

  5. Give the tunnel any name (for example, Subnet-10.0.0.0/24) and select Create tunnel.

  6. Select the operating system of your host machine.

  7. On your host machine, open a terminal window and run the commands shown in the Zero Trust dashboard. Those commands will install the WARP Connector, enable IP forwarding on the host, and connect WARP Connector to your Zero Trust organization.

  8. (Optional) Configure IP forwarding:

    Enable IP forwarding to persist after reboot

    Terminal window
    echo 'net.ipv4.ip_forward = 1' | sudo tee -a /etc/sysctl.d/99-warp-svc.conf
    sudo sysctl -p /etc/sysctl.d/99-warp-svc.conf

    Configure IP forwarding with iptables

    If you are setting up WARP Connector on a host with iptables enabled, make sure that your iptables FORWARD chain includes rules to accept the desired traffic. For testing and troubleshooting purposes, you can set the default policy for the WARP interface to ACCEPT:

    Terminal window
    iptables -A FORWARD -i CloudflareWARP -J ACCEPT
    iptables -A FORWARD -o CloudflareWARP -J ACCEPT
  9. To verify that the WARP Connector is connected to Cloudflare:

    Terminal window
    $ warp-cli status
    Status update: Connected

    Troubleshoot connection

    If WARP is disconnected, try the following troubleshooting strategies:

    • Run warp-cli connect.

    • If your private network uses a firewall to restrict Internet traffic, ensure that it allows the WARP ports and IPs.

    • Review your WARP daemon logs for information about why the connection is failing.

WARP Connector software is now installed but not yet routing traffic.

A dedicated device profile allows you to manage the WARP Connector host machine separately from WARP client user devices. WARP Connector hosts are registered to your Zero Trust organization with the email address warp_connector@<your-team-name>.cloudflareaccess.com. To set up a device profile for WARP Connector:

  1. Create a new profile that matches on the following expression:

    SelectorOperatorValue
    User emailiswarp_connector@<your-team-name>.cloudflareaccess.com
  2. In the profile settings, ensure that Service mode is set to Gateway with WARP.

3. Route traffic from subnet to WARP Connector

Depending on where you installed the WARP Connector, you may need to configure other devices on the subnet to route outbound requests through WARP Connector.

Option 1: Default gateway

If you installed WARP Connector on your router, no additional configuration is necessary. All traffic will use the router as the default gateway.

Default gateway routing configuration

Option 2: Alternate gateway

If you have access to the router but installed WARP Connector on another machine, you can configure the router to forward traffic to the WARP Connector. This typically involves adding a static route for the destination IPs that you want to connect to through Cloudflare. Refer to your router documentation for specific instructions on how to add an IP route.

Alternate gateway routing configuration

Add route to router

For example, for all traffic from the subnet to egress through WARP Connector, add a rule on the router that routes 0.0.0.0 to the WARP Connector host machine (10.0.0.100).

When a device on the subnet sends a request, the router will first redirect the traffic to the WARP Connector host. WARP Connector encrypts the traffic, changes its destination IP to the WARP ingress IP, and sends it back to the router. The router will now forward this encrypted traffic to Cloudflare.

Option 3: Intermediate gateway

If you do not have access to the router, you will need to configure each device on the subnet to egress through the WARP Connector machine instead of the default gateway.

Intermediate gateway routing configuration

Add route to devices

You can configure all traffic on a device to egress through WARP Connector with its local source IP. All traffic will be filtered by your Gateway network policies.

Terminal window
sudo ip route add default via <WARP-CONNECTOR-IP> dev eth0 metric 101

Ensure that the metric value is lower than other default gateways.

Verify routes

To validate subnet routing, check your routing table and ensure that traffic is routing through the CloudflareWARP virtual interface.

4. Test the WARP Connector

You can now test if traffic from your subnet routes through Cloudflare. For example,

  1. On the 10.0.0.2 device, run curl --ipv4 www.google.com.
  2. Check your Gateway DNS logs for queries from warp_connector@<your-team-name>.cloudflareaccess.com. Logs may take a few minutes to populate.
    flowchart LR
      subgraph subnet1[Subnet 10.0.0.0/24]
        device1["Device
        10.0.0.2"]--Request-->router1["WARP Connector
        10.0.0.1"]
      end
      router1-->C((Cloudflare))-->I{Internet}

Footnotes

  1. Check the system requirements. Package dependencies are the following: curl, gpg, iptables, iptables-persistent, lsb-core, and sudo.