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Configuration prerequisites
Before configuring OSPF network optimization, complete the following tasks:
•
Configure IP addresses for interfaces
•
Configure OSPF basic functions
Configuring OSPF packet timers
You can configure the following timers on OSPF interfaces as needed.
•
Hello timer—Interval for sending hello packets. It must be identical on OSPF neighbors. The longer
the interval, the lower the convergence speed, and the smaller the network load.
•
Poll timer—Interval for sending hello packets to a neighbor that is down on the NBMA network.
•
Dead timer—Interval within which if the interface receives no hello packet from the neighbor, it
declares the neighbor is down.
•
LSA retransmission timer—Interval within which if the interface receives no acknowledgement
packets after sending an LSA to the neighbor, it retransmits the LSA.
Follow these steps to configure timers for OSPF packets:
To do…
Use the command…
Remarks
Enter system view
system-view
—
Enter interface view
interface
interface-type
interface-number
—
Specify the hello
interval
ospf timer hello
seconds
Optional
The hello interval defaults to 10 seconds on P2P
and broadcast interfaces, and defaults to 30
seconds on P2MP and NBMA interfaces.
Specify the poll interval
ospf timer poll
seconds
Optional
The poll interval defaults to 120 seconds.
Specify the dead
interval
ospf timer dead
seconds
Optional
The default dead interval is 40 seconds on P2P
and broadcast interfaces and 120 seconds on
P2MP and NBMA interfaces.
Specify the
retransmission interval
ospf timer retransmit
interval
Optional
The retransmission interval defaults to 5
seconds.
NOTE:
•
The hello and dead intervals restore to default values after you change the network type for an interface.
•
The dead interval must be at least four times the hello interval on an interface.
•
The poll interval is at least four times the hello interval.
•
The retransmission interval must not be so small to avoid unnecessary LSA retransmissions. In general,
this value is bigger than the round-trip time of a packet between two neighbors.
