--- layout: "docs" page_title: "Connect - Configuration" sidebar_current: "docs-connect-config" description: |- A Connect-aware proxy enables unmodified applications to use Connect. A per-service proxy sidecar transparently handles inbound and outbound service connections, automatically wrapping and verifying TLS connections. --- # Connect Configuration There are many configuration options exposed for Connect. The only option that must be set is the "enabled" option on Consul Servers to enable Connect. All other configurations are optional and have reasonable defaults. ## Enable Connect on the Cluster The first step to use Connect is to enable Connect for your Consul cluster. By default, Connect is disabled. Enabling Connect requires changing the configuration of only your Consul _servers_ (not client agents). To enable Connect, add the following to a new or existing [server configuration file](/docs/agent/options.html). In HCL: ```hcl connect { enabled = true } ``` This will enable Connect and configure your Consul cluster to use the built-in certificate authority for creating and managing certificates. You may also configure Consul to use an external [certificate management system](/docs/connect/ca.html), such as [Vault](https://vaultproject.io). No agent-wide configuration is necessary for non-server agents. Services and proxies may always register with Connect settings, but they will fail to retrieve or verify any TLS certificates. This causes all Connect-based connection attempts to fail until Connect is enabled on the server agents. -> **Note:** Connect is enabled by default when running Consul in dev mode with `consul agent -dev`. ~> **Security note:** Enabling Connect is enough to try the feature but doesn't automatically ensure complete security. Please read the [Connect production guide](/docs/guides/connect-production.html) to understand the additional steps needed for a secure deployment. ## Built-In Proxy Options This is a complete example of all the configuration options available for the built-in proxy. Note that only the `service.connect.proxy.config` map is being described here, the rest of the service definition is shown for context and is [described elsewhere](/docs/connect/proxies.html#managed-proxies). ```javascript { "service": { "name": "web", "port": 8080, "connect": { "proxy": { "config": { "bind_address": "0.0.0.0", "bind_port": 20000, "local_service_address": "127.0.0.1:1234", "local_connect_timeout_ms": 1000, "handshake_timeout_ms": 10000, "upstreams": [ { "destination_type": "service", "destination_name": "redis", "destination_datacenter": "dc1", "local_bind_address": "127.0.0.1", "local_bind_port": 1234, "connect_timeout_ms": 10000 }, ] } } } } } ``` #### Configuration Key Reference * `bind_address` - The address the proxy will bind it's _public_ mTLS listener to. It defaults to the same address the agent binds to. * `bind_port` - The port the proxy will bind it's _public_ mTLS listener to. If not provided, the agent will attempt to assing one from its [configured proxy port range](/docs/agent/options.html#proxy_min_port) if available. By default the range is [20000, 20255] and the port is selected at random from that range. * `local_service_address` - The `[address]:port` that the proxy should use to connect to the local application instance. By default it assumes `127.0.0.1` as the address and takes the port from the service definition's `port` field. Note that allowing the application to listen on any non-loopback address may expose it externally and bypass Connect's access enforcement. It may be useful though to allow non-standard loopback addresses or where an alternative known-private IP is available for example when using internal networking between containers. * `local_connect_timeout_ms` - The number of milliseconds the proxy will wait to establish a connection to the _local application_ before giving up. Defaults to `1000` or 1 second. * `handshake_timeout_ms` - The number of milliseconds the proxy will wait for _incoming_ mTLS connections to complete the TLS handshake. Defaults to `10000` or 10 seconds. * `upstreams` - An array of upstream definitions for remote services that the proxied application needs to make outgoing connections to. Each definition has the following fields: * `destination_name` - [required] The name of the service or prepared query to route connect to. * `local_bind_port` - [required] The port to bind a local listener to for the application to make outbound connections to this upstream. * `local_bind_address` - The address to bind a local listener to for the application to make outbound connections to this upstream. * `destination_type` - Either `service` or `upstream`. The type of discovery query to use to find an instance to connect to. Defaults to `service`. * `destination_datacenter` - The datacenter to issue the discovery query too. Defaults to the local datacenter. * `connect_timeout_ms` - The number of milliseconds the proxy will wait to establish a connection to and complete TLS handshake with the _remote_ application or proxy. Defaults to `10000` or 10 seconds.