Reference Guide

Open Shortest Path First (OSPFv2) | 649
Usage
Information
In OSPF, flooding is the most resource-consuming task. The flooding algorithm, described in
RFC-2328, requires that OSPF flood LSAs (Link State Advertisements) on all interfaces, as governed
by LSA’s flooding scope (see Section 13 of the RFC). When multiple direct links connect two routers,
the RFC-2328 flooding algorithm generates significant redundant information across all links.
By default, FTOS implements an enhanced flooding procedure that dynamically and intelligently
determines when to optimize flooding. Whenever possible, the OSPF task attempts to reduce flooding
overhead by selectively flooding on a subset of the interfaces between two routers.
When flood-2328 is enabled, this command configures FTOS to flood LSAs on all interfaces.
graceful-restart grace-period
s z
Specifies the time duration, in seconds, that the router’s neighbors will continue to advertise the router
as fully adjacent regardless of the synchronization state during a graceful restart.
Syntax
graceful-restart grace-period seconds
To disable the grace period, enter no graceful-restart grace-period.
Parameters
Defaults
Not Configured
Command Modes
ROUTER OSPF
Command
History
Usage
Information
OSPF Graceful Restart is not supported on the S4810 system.
graceful-restart helper-reject
s z
Specify the OSPF router to not act as a helper during graceful restart.
Syntax
graceful-restart helper-reject ip-address
To return to default value, enter no graceful-restart helper-reject.
Parameters
Defaults
Not Configured
Command Modes
ROUTER OSPF
S6000
seconds
Time duration, in seconds, that specifies the duration of the restart process
before OSPF terminates the process.
Range: 40 to 3000 seconds
Version 9.0.2.0 Introduced on S6000.
Version 8.3.11.1 Introduced on Z9000
Version 7.8.1.0 Introduced support for Multi-Process OSPF.
S6000
ip-address
Enter the OSPF router-id, in IP address format, of the restart router that will
not act as a helper during graceful restart.