# Ports This section provides essential information about the ports used by the system, their primary purposes, and recommendations for exposure settings. ## Peering Ports - **Port:** 30303 - **Protocol:** TCP and UDP - **Purpose:** Peering with other nodes for synchronization of blockchain data. Nodes communicate through this port to maintain network consensus and share updated information. - **Exposure Recommendation:** This port should be exposed to enable seamless interaction and synchronization with other nodes in the network. ## Metrics Port - **Port:** 9001 - **Protocol:** TCP - **Purpose:** This port is designated for serving metrics related to the system's performance and operation. It allows internal monitoring and data collection for analysis. - **Exposure Recommendation:** By default, this port should not be exposed to the public. It is intended for internal monitoring and analysis purposes. ## HTTP RPC Port - **Port:** 8545 - **Protocol:** TCP - **Purpose:** Port 8545 provides an HTTP-based Remote Procedure Call (RPC) interface. It enables external applications to interact with the blockchain by sending requests over HTTP. - **Exposure Recommendation:** Similar to the metrics port, exposing this port to the public is not recommended by default due to security considerations. ## WS RPC Port - **Port:** 8546 - **Protocol:** TCP - **Purpose:** Port 8546 offers a WebSocket-based Remote Procedure Call (RPC) interface. It allows real-time communication between external applications and the blockchain. - **Exposure Recommendation:** As with the HTTP RPC port, the WS RPC port should not be exposed by default for security reasons. ## Engine API Port - **Port:** 8551 - **Protocol:** TCP - **Purpose:** Port 8551 facilitates communication between specific components, such as "reth" and "CL" (assuming their definitions are understood within the context of the system). It enables essential internal processes. - **Exposure Recommendation:** This port is not meant to be exposed to the public by default. It should be reserved for internal communication between vital components of the system.