Reference Guide

Open Shortest Path First (OSPFv2 and OSPFv3) | 475
• helper-reject neighbors—the router ID of each restart router that does not receive assistance from the
configured router.
•
mode—the situation or situations that trigger a graceful restart.
•
role—the role or roles the configured router can perform.
You enable OSPF graceful restart in CONFIGURATION ROUTER OSPF mode.
When you configure a graceful restart, the
show run ospf command (Figure 24-17) displays information
similar to the following.
Note: By default, OSPF graceful restart is disabled.
Command Syntax Command Mode Usage
graceful-restart
grace-period
seconds
CONFIG-ROUTER-
OSPF-id
Enable OSPF graceful-restart globally and set the grace period.
Seconds range: between 40 and 3000
This is the period of time that an OSPF router’s neighbors will advertise it as fully adjacent,
regardless of the synchronization state, during a graceful restart.
OSPF terminates this process when the grace period ends.
graceful-restart
helper-reject router-id
CONFIG-ROUTER-
OSPF-id
Enter the Router ID of the OSPF helper router from which the router
does not accept graceful restart assistance.
This applies to the specified router only.
IP Address: A.B.C.D
graceful-restart mode
[planned-only |
unplanned-only]
CONFIG-ROUTER-
OSPF-id
Specify the operating mode in which graceful-restart functions.
FTOS supports the following options:
• Planned-only. The OSPF router supports graceful-restart for
planned restarts only. A planned restart is when the user
manually enters a fail-over command to force the primary RPM
over to the secondary RPM. During a planned restart, OSPF
sends out a Grace LSA before the system switches over to the
secondary RPM. OSPF also is notified that a planned restart is
happening.
• Unplanned-only. The OSPF router supports graceful-restart for
only unplanned restarts. During an unplanned restart, OSPF
sends out a Grace LSA once the secondary RPM comes online.
By default, OSPF supports both planned and unplanned restarts. Selecting one or the other
mode restricts OSPF to the single selected mode.
graceful-restart role
[helper-only | restart-only]
CONFIG-ROUTER-
OSPF-id
Configure the graceful restart role or roles that this OSPF router
performs. FTOS supports the following options:
• Helper-only. The OSPF router supports graceful-restart only as a
helper router.
• Restart-only. The OSPF router supports graceful-restart only
during unplanned restarts.
By default, OSPF supports both restarting and helper roles. Selecting one or the other role
restricts OSPF to the single selected role.