Which process is responsible for controlling all interfaces on a Junos device?

The `rpd` (routing protocol daemon) manages routing protocols and the routing table, not the direct control of interfaces.

The `chassisd` (chassis daemon) controls the physical hardware components of the router, such as sensors, power, and fans, but not the network interfaces themselves.

The `dcd` (device control daemon) is the Junos OS process responsible for controlling all device interfaces, including their configuration, operational state, and monitoring of physical and logical interfaces.

The `mgd` (management daemon) handles management interfaces, such as CLI, Telnet, and SSH access, and applies configuration changes, but it does not directly control the operational state of network interfaces.