Consul ports reference

This page provides reference information about the required ports that Consul exposes for its operations.

You can change or disable Consul's default ports in the agent configuration file or using the consul agent CLI command.

Overview

The exact ports that Consul requires depend on your network's specific configuration. For example, the port for WAN serf communication is only required when using WAN federation.

There are slight differences between the port requirements for Consul servers and clients. When a Consul server has services, proxies, or gateways registered to it, then it acts as both a server and client.

HCP Consul Dedicated servers have distinct port assignments. For more information, refer to cluster management in the HCP documentation.

Consul servers

The following table lists port names, their function, their network protocols, their default port numbers, whether they are enabled or disabled by default, port assignments for HCP Consul Dedicated server clusters, and the direction of traffic from the Consul server's perspective.

DNS

The following table lists information about the server agent's DNS port defaults:

This port receives incoming traffic from workloads to resolve Consul DNS requests.

The server's DNS port does not need to be open when DNS queries are sent to Consul clients. Consul does not use this port for internal communication between servers, clients, dataplanes, gateways, and Envoy proxies.

If you configure recursors in Consul to upstream DNS servers, then you need outbound access to those servers on port 53.

To resolve Consul DNS requests when using HCP Consul Dedicated, we recommend running Consul clients and resolving DNS against the clients. If your use case cannot accommodate this recommendation, open a support ticket.

HTTP

The following table lists information about the Consul server API's HTTP port defaults:

This port receives incoming traffic from workloads that make HTTP API calls.

The server's HTTP port does not need to be open when Consul clients service all HTTP API calls. Consul does not use this port for internal communication between servers, clients, dataplanes, gateways, and Envoy proxies.

The Consul CLI uses the HTTP port to interact with Consul by default.

HCP Consul Dedicated does not support the HTTP port.

HTTPS

The following table lists information about the Consul server API's HTTPS port defaults:

This port receives incoming traffic from workloads that make HTTPS API calls.

The server HTTPS port does not need to be open when Consul clients service all HTTPS API calls. Consul does not use this port for internal communication between servers, clients, dataplanes, gateways, and Envoy proxies.

This port is disabled by default. You can enable it in the agent configuration file or using the consul agent CLI command.

HCP Consul Dedicated assigns port 443 to HCP Consul Dedicated clusters, instead of the default 8501.

gRPC

The following table lists information about the Consul API's gRPC port defaults:

When using Consul Dataplane, this port receives incoming traffic from the dataplanes.

We recommend using gRPC TLS instead, so this port is disabled by default. You can enable it in the agent configuration file or using the consul agent CLI command.

HCP Consul Dedicated does not support the gRPC port.

gRPC TLS

The following table lists information about the Consul API's gRPC with TLS port defaults:

This port receives incoming traffic from the dataplanes when using Consul Dataplane instead of client agents. We recommend using 8503 as your conventional gRPC port number because it allows some tools to work automatically.

In deployments with cluster peering connections, this port provides incoming and outgoing access between remote server peers. Specifically, the dialing peer needs outgoing access and the accepting peer needs incoming access. The address dialed depends on whether or not the cluster peering connection uses mesh gateways and whether the mesh gateway is in remote or local mode:

• When not using mesh gateways, servers dial the remote server addresses directly.
• When using mesh gateways in local mode, servers dial the local mesh gateway.
• When using mesh gateways in remote mode, servers dial the remote mesh gateway.

In both local and remote cases, incoming traffic comes from the mesh gateways.

HCP Consul Dedicated assigns port 8502 to clusters, instead of the default 8503.

Server RPC

The following table lists information about the Server RPC port defaults:

This port sends and receives traffic between Consul servers in the same datacenter. It also receives incoming traffic from Consul clients in the same datacenter.

When using WAN federation without mesh gateways, incoming and outgoing traffic on this port is required between all federated servers.

When using WAN federation with mesh gateways, Consul servers must accept server RPC requests from mesh gateways in the local datacenter. The mesh gateway mode determines the path that outgoing traffic takes, either direct to remote gateways or first to local gateways, but incoming traffic always comes through the local mesh gateways.

LAN serf

The following table lists information about the LAN serf port defaults:

This port sends and receives traffic from Consul clients and other Consul servers in the same datacenter. Refer to gossip protocol for more information.

When running Enterprise deployments that use multiple admin partitions, all Consul clients across all partitions still require access to this port on all servers. Servers also require access to this port on all clients.

WAN serf

The following table lists information about the WAN serf port defaults:

This port sends and receives traffic between Consul servers in a federated network. WAN-federated networks require one cluster to serve as the primary datacenter while the others function as secondary datacenters. Refer to Enabling WAN Federation Control Plane Traffic for additional information.

When using WAN federation without mesh gateways, incoming and outgoing traffic on this port is required between all federated servers.

When using WAN federation with mesh gateways, Consul servers must accept WAN Serf requests from mesh gateways in the local datacenter, regardless of which mesh gateway mode is used. As a result, traffic always comes from a local mesh gateway.

Consul clients

The following table lists port names, their function, their network protocols, their default port numbers, whether they are enabled or disabled by default, and the direction of traffic from the Consul client's perspective.

Client DNS

The following table lists information about the client agent's DNS port defaults:

This port receives incoming traffic from workloads to resolve Consul DNS requests. Consul does not use this port for internal communication between servers, clients, dataplanes, gateways, and Envoy proxies.

If you configure recursors in Consul to upstream DNS servers, then you need outbound access to those servers on port 53.

Client HTTP

The following table lists information about the Consul client's HTTP port defaults:

This port receives incoming traffic from workloads that make HTTP API calls. Consul does not use this port for internal communication between servers, clients, dataplanes, gateways, and Envoy proxies.

The Consul CLI uses the HTTP port to interact with Consul by default.

Client HTTPS

The following table lists information about the Consul client's HTTPS port defaults:

This port receives incoming traffic from workloads that make HTTPS API calls. Consul does not use this port for internal communication between servers, clients, dataplanes, gateways, and Envoy proxies.

This port is disabled by default. You can enable it in the agent configuration file or using the consul agent CLI command.

When this port is enabled, the Consul CLI uses it to interact with Consul.

Client gRPC

The following table lists information about the Consul client's gRPC port defaults:

This port receives incoming traffic from the gateways and Envoy proxies registered to this client.

We recommend using gRPC TLS instead.

Client gRPC TLS

The following table lists information about the Consul client's gRPC with TLS port defaults:

This port receives incoming traffic from the gateways and Envoy proxies registered to this client. We recommend using 8503 as your conventional gRPC port number, as it allows some tools to work automatically.

This port is disabled by default. You can enable it in the agent configuration file or using the consul agent CLI command.

Client LAN serf

The following table lists information about the Consul client's LAN serf port defaults:

This port sends and receives traffic from Consul clients and Consul servers in the same datacenter. Refer to gossip protocol for more information.

When running Enterprise deployments that use network segments or admin partitions, Consul clients within a segment or partition require access to each other's ports. Clients do not require port access across segments or partitions.