---
layout: docs
page_title: Mesh Gateways between Peered Clusters
description: >-
  Mesh gateways are specialized proxies that route data between services that cannot communicate directly. Learn how to enable service-to-service traffic across clusters in different datacenters or admin partitions that have an established peering connection.
---

# Mesh Gateways between Peered Clusters

Mesh gateways are required for you to route service mesh traffic between peered Consul clusters. Clusters can reside in different clouds or runtime environments where general interconnectivity between all services in all clusters is not feasible.

At a minimum, a peered cluster exporting a service must have a mesh gateway registered.
For Enterprise, this mesh gateway must also be registered in the same partition as the exported service(s).
To use the `local` mesh gateway mode, there must also be a mesh gateway regsitered in the importing cluster.

Unlike mesh gateways for WAN-federated datacenters and partitions, mesh gateways between peers terminate mTLS sessions to decrypt data to HTTP services and then re-encrypt traffic to send to services. Data must be decrypted in order to evaluate and apply dynamic routing rules at the destination cluster, which reduces coupling between peers.

## Prerequisites

To configure mesh gateways for cluster peering, make sure your Consul environment meets the following requirements:

- Consul version 1.14.0 or newer.
- A local Consul agent is required to manage mesh gateway configuration.
- Use [Envoy proxies](/docs/connect/proxies/envoy). Envoy is the only proxy with mesh gateway capabilities in Consul.

## Configuration

Configure the following settings to register and use the mesh gateway as a service in Consul.

### Gateway registration

- Specify `mesh-gateway` in the `kind` field to register the gateway with Consul.
- Define the `Proxy.Config` settings using opaque parameters compatible with your proxy. For Envoy, refer to the [Gateway Options](/docs/connect/proxies/envoy#gateway-options) and [Escape-hatch Overrides](/docs/connect/proxies/envoy#escape-hatch-overrides) documentation for additional configuration information.

Alternatively, you can also use the CLI to spin up and register a gateway in Consul. For additional information, refer to the [`consul connect envoy` command](/commands/connect/envoy#mesh-gateways).

### Sidecar registration

- Configure the `proxy.upstreams` parameters to route traffic to the correct service, namespace, and peer. Refer to the [`upstreams` documentation](/docs/connect/registration/service-registration#upstream-configuration-reference) for details.
- The service `proxy.upstreams.destination_name` is always required.
- The `proxy.upstreams.destination_peer` must be configured to enable cross-cluster traffic.
- The `proxy.upstream/destination_namespace` configuration is only necessary if the destination service is in a non-default namespace.

### Service exports

- Include the `exported-services` configuration entry to enable Consul to export services contained in a cluster to one or more additional clusters. For additional information, refer to the [Exported Services documentation](/docs/connect/config-entries/exported-services).

### ACL configuration

- If ACLs are enabled, you must add a token granting `service:write` for the gateway's service name and `service:read` for all services in the Enterprise admin partition or OSS datacenter to the gateway's service definition. These permissions authorize the token to route communications for other Consul service mesh services.

### Modes

Modes are configurable as either `remote` or `local` for mesh gateways that connect peered clusters. 
The `none` setting is invalid for mesh gateways in peered clusters and will be ignored by the gateway.
By default, all proxies connecting to peered clusters use mesh gateways in [remote mode](/docs/connect/gateways/mesh-gateway/service-to-service-traffic-wan-datacenters#remote).