Dell Networking 2024 Reference Manual page 1235

Default Configuration
By default, OSPF is not in stub router mode.
Command Mode
OSPFv2 Global Configuration mode
User Guidelines
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 LsInfinity. 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.
One can administratively force OSPF into stub router mode. OSPF remains
in stub router mode until OSPF is taken out of stub router mode.
Alternatively, one can configure OSPF to start in stub router mode for a
specific period of time after the router boots up.
If the summary LSA metric is set to 16,777,215, other routers will skip the
summary LSA when they compute routes.
If the router is configured to enter stub router mode on startup (max-metric
router-lsa on-startup), and one then enters max-metric router lsa, there is no
change. If OSPF is administratively in stub router mode (the max-metric
router-lsa command has been given), and one configures OSPF to enter stub
router mode on startup (max-metric router-lsa on-startup), OSPF exits stub
router mode (assuming the startup period has expired) and the configuration
is updated.
The command no max-metric router-lsa clears either type of stub router
mode (always or on-startup) and resets the summary-lsa option. If OSPF is
configured to enter global configuration mode on startup, and during normal
operation one wants to immediately place OSPF in stub router mode, one
may issue the command no max-metric router-lsa on-startup. The command
no max-metric router-lsa summary-lsa causes OSPF to send summary LSAs
with metrics computed using normal procedures defined in RFC 2328.
1235
OSPF Commands