5000 Series Layer 2/3 Managed Data Center Switch CLI Reference Guide
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routing around the restarting router. A helpful neighbor will consider a link down with the restarting router
to constitute a topology change, regardless of the strict LSA checking configuration.
This command can be used to require that an OSPF helpful neighbor exit the helper mode whenever a
topology change occurs.
The
no
command allows the OSPF to continue as a helpful neighbor regardless of any topology changes.
nsf [ietf] helper strict-lsa-checking
no nsf [ietf] helper strict-lsa-checking
Parameters
ietf
(Optional) This keyword is accepted but not required.
Default
The default is Enabled.
Command Mode
Router OSPFv3 Config
OSPFv3 Stub Router Commands
8-108 max-metric router-Isa
Use this command in the Router OSPFv3 Global Configuration mode to configure OSPFv3 to enter the
stub router mode. When OSPFv3 is in the stub router mode, OSPFv3 sets the metric for the nonstub links
in its router LSA to MaxLinkMetric, thus causing other routers to compute very lengthy paths through the
stub router and to prefer any alternate path. Thus, when alternate routes are available, doing so
eliminates all transit traffic through the stub router. The stub router mode is useful when a router is being
added to or removed from a network or for avoiding transient routes when a router reloads.
OSPFv3 can be forced into the stub router mode administratively. OSPFv3 remains in the stub router
mode until the user takes OSPFv3 out of the stub router mode. Alternatively, OSPF can be configured to
start in the stub router mode for a configurable period of time after the router boots up.
lf the summary LSA metric is set to 16,777,215, then other routers will skip the summary LSA when those
routers compute routes.
lf a router has been configured to enter the stub router mode on startup (max-metric router-Isa on-startup),
and then to enter max-metric router Isa, there is no change. lf OSPFv3 is administratively placed in the
stub router mode (i.e., if the max-metric router-Isa command has been given), and the user then
configures OSPFv3 to enter the stub router mode on startup (max-metric router-Isa on-startup), then
OSPFv3 exits the stub router mode (assuming that the startup period has expired), and the configuration
is then updated. If no parameters are sspecified, then the stub router mode sends only maximum metric
values for router LSAs.
The
no
command can be used in the OSPFv3 Router Configuration mode to disable the stub router mode.
Using the command clears either type of stub router mode (that is, always or on-startup) and resets all
LSA options. In the event that the OSPF is configured to enter the global configuration mode on startup,
and if during normal operation the user would like to immediately place OSPF in the stub router mode,
then the command
no max-metric router-Isa on-startup
should be issued. Using the command no max-
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