Flux Node Network Setup

Created by John K, Modified on Sat, 23 Sep 2023 at 03:59 PM by John K

To ensure proper operation of your Flux Node please be sure to setup your networking appropriately. Below we will cover single and multi-node network requirements.

Single Node

It is recommended to use UPnP, this requires a router that supports the UPnP protocol.

The widely accepted solution is to use a pfSense firewall/router.


The other option for a Single node setup is to place the node in the router's DMZ (demilitarized zone), effectively exposing all traffic to your Node. The Flux node has a firewall (UFW) that is installed and configured during the node setup process with multitoolbox. This firewall will handle opening the proper ports for the node to have access to the internet.

Port forwarding is no longer recommended after Flux OS version 4.0.0. Please see the release notes below.

Flux OS Release Notes v4.0.0

UPnP Setup for Single Node

UPnP stands for universal plug and play which essentially allows devices on the network to request ports to be opened by the router for incoming traffic. UPnP can be an easier solution if the router is supported and sticks to proper UPnP standards.

To setup UPnP on the router, first set the node to a static or or dhcp reservation so the local IP for the node always stays the same. Next, remove any port forwarding that is setup for the node (if any). Finally, enable UPnP and reboot the router before proceeding to the next step.

To enable UPnP on the Flux node, run Multitoolbox option 14 and select an API port for the node. It is typically suggested to start from the lowest port and work up. The lowest port is 16127.

Multi-node Configuration

The maximum number of Flux nodes supported on a single external IP address is 8.

UPnP is REQUIRED to run more than a single node on the same external IP address. Port Forwarding WILL NOT work properly on most consumer grade routers.

The UPnP setup is exactly the same as a single node setup except when you run multitoolbox option 14 you will want to choose a different API port for each node. Also, please be sure to set each node to a static or dhcp reservation in your router settings.

Network Diagnostic Tools

After you have installed your node and you are going through the final stages to make sure the node is ready to be started in Zelcore, you will want to ensure your ports are open from the outside.

There is a simple command line tool that you can use to test your ports and UPnP status all at once. If ports show as closed you will want to investigate your networking setup.

bash -i <(curl -s https://raw.githubusercontent.com/JKTUNING/Flux-Node-Tools/main/flux_node_viewer.sh node)

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