# Fullnode Network Connections

When running a fullnode on an Aptos network, you can configure your node's network connections for a few different purposes. For example, you can add a seed peer to your node's configuration YAML to connect your node to a specific peer of your choosing. Or you can create a static network identity for your node to allow other nodes to connect to you, as described in Network Identity For Fullnode.

This document describes how to configure the network of your fullnode for different deployments and requirements, including:

• Allowing fullnodes to connect to your node.
• Connecting your fullnode to an Aptos blockchain deployment.
• Connecting your fullnode to seed peers.
• Configuring priority access for other fullnodes.
• Configuring your fullnode as a private fullnode.

## Allowing fullnodes to connect to your node​

Before you proceed

Before allowing other fullnodes to connect to your fullnode, be sure to create a fullnode identity. See Network Identity For Fullnode.

Once you start your fullnode with a static identity you can allow others to connect to your fullnode:

tip

In the below steps, the port numbers used are for illustration only. You can use your choice of port numbers. See Ports and port settings for an explanation of port settings and how they are used.

• Make sure you open port 6180 (or 6182, for example, depending on which port your node is listening to) and that you open your firewall.
• If you are using Docker, simply add - "6180:6180" or - "6182:6182" under ports in your docker-compose.yaml file.
• Share your fullnode static network identity with others. They can then use it in the seeds key of their fullnode.yaml file to connect to your fullnode. See the section below.
• Make sure the port number you put in the addresses matches the one you have in the fullnode configuration file fullnode.yaml (for example, 6180 or 6182).

Share your fullnode static network identity in the following format in our Discord to advertise your node. Note, the Discord channel to share your identity may differ depending on the blockchain deployment you're running in. See Aptos Blockchain Deployments for more information.

<Peer_ID>:  addresses:  # with DNS  - "/dns4/<DNS_Name>/tcp/<Port_Number>/noise-ik/<Public_Key>/handshake/0"  role: Upstream<Peer_ID>:  addresses:  # with IP  - "/ip4/<IP_Address>/tcp/<Port_Number>/noise-ik/<Public_Key>/handshake/0"  role: Upstream

For example:

B881EA2C174D8211C123E5A91D86227DB116A44BB345A6E66874F83D8993F813:  addresses:  - "/dns4/pfn0.node.devnet.aptoslabs.com/tcp/6182/noise-ik/B881EA2C174D8211C123E5A91D86227DB116A44BB345A6E66874F83D8993F813/handshake/0"  role: "Upstream"B881EA2C174D8211C123E5A91D86227DB116A44BB345A6E66874F83D8993F813:  addresses:  - "/ip4/100.20.221.187/tcp/6182/noise-ik/B881EA2C174D8211C123E5A91D86227DB116A44BB345A6E66874F83D8993F813/handshake/0"  role: "Upstream"
tip

Peer ID is synonymous with AccountAddress. See NetworkAddress to see how the addresses key value is constructed.

## Connecting your fullnode to an Aptos blockchain deployment​

When running a fullnode on an Aptos blockchain deployment, your node will be able to discover other nodes in the network automatically, e.g., using the genesis blob or the network addresses of the validators and validator fullnodes registered on the blockchain. Be sure to download the correct genesis blob and waypoint for your fullnode to ensure your node connects to the correct Aptos blockchain deployment. See Aptos Blockchain Deployments for more information.

## Connecting your fullnode to seed peers​

All Aptos fullnodes are configured to accept a maximum number of network connections. As a result, if the network is experiencing high network connection volume, your fullnode might not able to connect to the default nodes in the network and you may see several errors in your node's logs, e.g., No connected AptosNet peers! or Unable to fetch peers to poll!.

If this happens continuously, you should manually add seed peers to your node's configuration file to connect to other nodes.

tip

You may see No connected AptosNet peers! or Unable to fetch peers to poll! in your node's error messages. This is normal when the node is first starting. Wait for the node to run for a few minutes to see if it connects to peers. If not, follow the below steps:

See below for a few seed peer addresses you can use in your public_full_node.yaml file. The peers you choose will differ based on the blockchain deployment your node is running in.

tip

You can also use the fullnode addresses provided by the Aptos community. Anyone already running a fullnode can provide their address for you to connect. See the Aptos Discord.

### Devnet seed peers​

To add seeds to your devnet fullnode, add these to your public_full_node.yaml configuration file under your discovery_method, as shown in the below example:

...full_node_networks:    - discovery_method: "onchain"      listen_address: ...      seeds: # All seeds are declared below        bb14af025d226288a3488b4433cf5cb54d6a710365a2d95ac6ffbd9b9198a86a:            addresses:            - "/dns4/pfn0.node.devnet.aptoslabs.com/tcp/6182/noise-ik/bb14af025d226288a3488b4433cf5cb54d6a710365a2d95ac6ffbd9b9198a86a/handshake/0"            role: "Upstream"        7fe8523388084607cdf78ff40e3e717652173b436ae1809df4a5fcfc67f8fc61:            addresses:            - "/dns4/pfn1.node.devnet.aptoslabs.com/tcp/6182/noise-ik/7fe8523388084607cdf78ff40e3e717652173b436ae1809df4a5fcfc67f8fc61/handshake/0"            role: "Upstream"        f6b135a59591677afc98168791551a0a476222516fdc55869d2b649c614d965b:            addresses:            - "/dns4/pfn2.node.devnet.aptoslabs.com/tcp/6182/noise-ik/f6b135a59591677afc98168791551a0a476222516fdc55869d2b649c614d965b/handshake/0"            role: "Upstream"...

## Configuring priority access for other fullnodes​

To configure your fullnode to allow another fullnode to connect to it even when your fullnode has hit the maximum number of available network connections, follow this method:

In the configuration file for your fullnode add the other fullnode as a seed peer with the Downstream role. This will allow the other fullnode to connect directly to you with priority access. In your fullnode configuration file, add:

seeds:  <other fullnode account>    addresses:    - <address of the other fullnode>    role: Downstream # Allows the node to connect to us

Similarly, to make the other fullnode connect to yours, add the following to the other fullnode's configuration file:

seeds:  <your fullnode account>    addresses:    - <address of your fullnode>    role: PreferredUpstream # Allows the node to connect to the seed peer

## Configuring your fullnode as a private fullnode​

You can also configure your fullnode as a private fullnode should you wish. What this means is that your fullnode will not allow unauthenticated connections, specifically, any node that is not a validator, validator fullnode, or seed peer will be unable to connect to your fullnode.

To configure your fullnode as a private fullnode, add the following to your fullnode configuration file. Note, you should add this to the first network entry in the full_node_networks configuration:

...full_node_networks:  - discovery_method: "onchain"    listen_address: ...    max_inbound_connections: 0  # Prevents any unauthenticated inbound connections    mutual_authentication: true  # Requires authenticated connections    ......