--- layout: docs page_title: Connect - Built-in Proxy description: Consul Connect comes with a built-in proxy for testing and development. --- # Built-In Proxy Options ~> **Note:** The built-in proxy is not supported for production deployments. It does not support many of the Connect service mesh features, and is not under active development. The [Envoy proxy](/docs/connect/proxies/envoy) should be used for production deployments. Consul comes with a built-in L4 proxy for testing and development with Consul Connect service mesh. ## Proxy Config Key Reference Below is a complete example of all the configuration options available for the built-in proxy. ```json { "service": { ... "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": [...] }, "upstreams": [ { ... "config": { "connect_timeout_ms": 1000 } } ] } } } } ``` All fields are optional with a reasonable default. - `bind_address` - The address the proxy will bind its _public_ mTLS listener to. It defaults to the same address the agent binds to. - `bind_port` - The port the proxy will bind its _public_ mTLS listener to. If not provided, the agent will assign a random port from its configured proxy port range specified by [`sidecar_min_port`](/docs/agent/config/config-files#sidecar_min_port) and [`sidecar_max_port`](/docs/agent/config/config-files#sidecar_max_port). - `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`- **Deprecated** Upstreams are now specified in the `connect.proxy` definition. Upstreams specified in the opaque config map here will continue to work for compatibility but it's strongly recommended that you move to using the higher level [upstream configuration](/docs/connect/registration/service-registration#upstream-configuration-reference). ## Proxy Upstream Config Key Reference All fields are optional with a reasonable default. - `connect_timeout_ms` - The number of milliseconds the proxy will wait to establish a TLS connection to the discovered upstream instance before giving up. Defaults to `10000` or 10 seconds.