How to Restart and Request System-wide Functions with Junos
The operational mode of Junos network operating system provides commands for restarting and resetting individual processes as well as rebooting the device and upgrading its system software.
Restart: Allows you to restart most Junos processes within operational mode. Junos is a modular operating system whereby independent processes run in their own protected memory space. As such, these processes (called daemons) can be independently managed.
Request: A set of commands that you can use to perform system-wide functions such as rebooting, upgrading, and shutting down the device. This group also provides you with the ability to put individual components online, take them offline, and restart them without having to reboot the entire device.
Although a process runs independently in the operating system, take special care when using the restart command. For example, a restart of the SNMP process is only disruptive to SNMP, but a restart of routing could have drastic consequences in your network by disrupting and resetting its routing paths.
To restart a specific routing protocol, such as OSPF, you can deactivate and then reactivate it in configuration mode. When a problem exists with only one protocol, this approach is better than restarting the entire routing daemon of Junos, which affects all the routing protocols.