Graceful shutdown of OSPF routing

OSPF routing can be gracefully shut down on switches without losing packets that are in transit. OSPF neighbors are informed that the router should not be used for forwarding traffic, which allows for maintenance on the switch without interrupting traffic in the network. There is no effect on the saved switch configuration

Prior to a switch shutdown, the CLI/SNMP reload command or the CLI boot command is executed to initiate the sending of OSPF "empty hello list" messages on the interfaces that are part of the OSPF routing configuration. After a small delay (approximately 2 seconds) that allows the messages to be transmitted on all applicable interfaces, the boot or reload command continues.