Ospfv2 Stub Router Commands - D-Link 5000 Series Cli Reference Manual

5000 Series Layer 2/3 Managed Data Center Switch CLI Reference Guide
7-180 nsf helper strict-Isa-checking
The restarting router is unable to react to topology changes. In particular, the restarting router will not
immediately update its forwarding table; therefore, a topology change may introduce forwarding loops or
black holes that persist until the graceful restart completes. By exiting the graceful restart on a topology
change, a router tries to eliminate the loops or black holes as quickly as possible by routing around the
restarting router. A helpful neighbor considers a link down with the restarting router to be a topology
change, regardless of the strict LSA checking configuration.
Use this command to require that an OSPF helpful neighbor exit helper mode whenever a topology
change occurs.
Use the no command to allow OSPF to continue as a helpful neighbor in spite of topology changes.
nsf [ietf] helper strict-lsa-checking
no nsf [ietf] helper strict-lsa-checking
Parameters
ietf
Default
The default is Enabled.
Command Mode
OSPF Router Config

OSPFv2 Stub Router Commands

7-181 max-metric router-Isa
To configure OSPF to enter stub router mode, use this command in Router OSPF Global Configuration
mode. When OSPF is in stub router mode, as defined by RFC 3137, OSPF sets the metric in the non-
stub links in its router LSA to Lslnfinity. Other routers therefore compute very long paths through the stub
router, and prefer any alternate path. Doing so eliminates all transit traffic through the stub router, when
alternate routes are available. Stub router mode is useful when adding or removing a router from a
network or to avoid transient routes when a router reloads.
You can administratively force OSPF into stub router mode, where it will remain until you take it out of
stub router mode. Alternatively, you can configure OSPF to start in stub router mode for a configurable
period of time after the router boots up.
If you set the summary LSA metric to 16,777,215, other routers will skip the summary LSA when they
compute routes.
if you have configured the router to enter stub router mode on startup (max-metric router-Isa on-startup),
and then enter max-metric router Isa, there is no change. If OSPF is administratively in stub router mode
(the max-metric router-Isa command has been given), and you configure OSPF to enter stub router mode
on startup (max-metric router-Isa on-startup), OSPF exits stub router mode (assuming the startup period
has expired) and the configuration is updated.
(Optional) This keyword is accepted but not required.
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