Install Guide

● role — the role or roles the configured router can perform.
NOTE: By default, OSPFv2 graceful restart is disabled.
To enable and configure OSPFv2 graceful restart, use the following commands.
1. Enable OSPFv2 graceful-restart globally and set the grace period.
CONFIG-ROUTEROSPF- id mode
graceful-restart grace-period seconds
The seconds range is from 40 and 3000.
This setting is the time that an OSPFv2 router’s neighbors advertises it as fully adjacent, regardless of the synchronization
state, during a graceful restart. OSPFv2 terminates this process when the grace period ends.
2. Enter the Router ID of the OSPFv2 helper router from which the router does not accept graceful restart assistance.
CONFIG-ROUTEROSPF- id mode
graceful-restart helper-reject router-id
● Planned-only — the OSPFv2 router supports graceful-restart for planned restarts only. A planned restart is when you
manually enter 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 OSPFv2 router supports graceful-restart for only unplanned restarts. During an unplanned
restart, OSPF sends out a Grace LSA after the secondary RPM comes online.
By default, OSPFv2 supports both planned and unplanned restarts. Selecting one or the other mode restricts OSPFv2 to the
single selected mode.
3. Configure the graceful restart role or roles that this OSPFv2 router performs.
CONFIG-ROUTEROSPF- id mode
graceful-restart role [helper-only | restart-only]
Dell EMC Networking OS supports the following options:
● Helper-only: the OSPFv2 router supports graceful-restart only as a helper router.
● Restart-only: the OSPFv2 router supports graceful-restart only during unplanned restarts.
By default, OSPFv2 supports both restarting and helper roles. Selecting one or the other role restricts OSPFv2 to the single
selected role.
To disable OSPFv2 graceful-restart after you have enabled it, use the no graceful-restart grace-period command in
CONFIG-ROUTEROSPF- id mode. The command returns OSPF graceful-restart to its default state.
NOTE:
The Helper mode is enabled by default on the device. To enable the restart mode also on the device, you must
configure the grace period using the graceful-restart grace-period command. After you enable restart mode the
router advertises the neighbor as fully adjacent during a restart.
For more information about OSPF graceful restart, refer to the Dell EMC Networking OS Command Line Reference Guide.
When you configure a graceful restart on an OSPFv2 router, the show run ospf command displays information similar to the
following.
DellEMC#show run ospf
!
router ospf 1
graceful-restart grace-period 300
graceful-restart role helper-only
graceful-restart mode unplanned-only
graceful-restart helper-reject 10.1.1.1
graceful-restart helper-reject 20.1.1.1
network 10.0.2.0/24 area 0
DellEMC#
Creating Filter Routes
To filter routes, use prefix lists. OSPF applies prefix lists to incoming or outgoing routes.
Incoming routes must meet the conditions of the prefix lists. If they do not, OSPF does not add the route to the routing table.
Configure the prefix list in CONFIGURATION PREFIX LIST mode prior to assigning it to the OSPF process.
Open Shortest Path First (OSPFv2 and OSPFv3)
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