Operation Manual – IPv4 Routing
H3C S5500-EI Series Ethernet Switches
Chapter 3 OSPF Configuration
3-21
After an OSPF GR Restarter restarts OSPF, it needs to perform the following two tasks
in order to re-synchronize its LSDB with its neighbors.
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To obtain once again effective OSPF neighbor information, supposing the
adjacencies are not changed.
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To obtain once again LSDB contents.
Before the restart, the GR Restarter originates Grace-LSAs to negotiate the GR
capability. During the restart, the GR Helpers continue to advertise their adjacencies
with the GR Restarter.
After the restart, the GR Restarter will send an OSPF GR signal to its neighbors that will
not reset their adjacencies with it. In this way, the GR Restarter can restore the
neighbor table upon receiving the responses from neighbors.
After reestablishing neighbor relationships, the GR Restarter will synchronize the LSDB
and exchange routing information with all adjacent GR-capable neighbors. After that,
the GR Restarter will update its own routing table and forwarding table based on the
new routing information and remove the stale routes. In this way, the OSPF routing
convergence is complete.
3.1.7 Protocols and Standards
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RFC 1765:OSPF Database Overflow
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RFC 2328: OSPF Version 2
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RFC 3101: OSPF Not-So-Stubby Area (NSSA) Option
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RFC 3137: OSPF Stub Router Advertisement
3.2 OSPF Configuration Task List
Complete the following tasks to configure OSPF:
Task
Remarks
Configuring OSPF Basic Functions
Required
Configuring OSPF Area Parameters
Optional
Configuring the OSPF Network Type for an
Interface
Optional
Configuring an NBMA Neighbor
Optional
Configuring
OSPF Network
Types
Configuring a Router Priority for an OSPF Interface
Optional