H3C S7500 Series Ethernet Switches Operation Manual

Operation Manual – Routing Protocol
H3C S7500 Series Ethernet Switches Chapter 4 OSPF Configuration
4-20
The dead time on an interface must be at least four times of the Hello interval on the
same interface.
After a router sends an LSA to a neighbor, it waits for an acknowledgement packet
from the neighbor. If the router receives no acknowledgement packet from the
neighbor within the retransmission interval, it retransmits the LSA to the neighbor.
Follow these steps to configure OSPF timers:
To do... Use the command... Remarks
Enter system view
system-view
—
Enter interface view
interface
interface-type
interface-number
—
Set the hello interval
on the interface
ospf timer hello
seconds
Optional
By default, p2p and broadcast
interfaces send Hello packets
every 10 seconds; while p2mp
and NBMA interfaces send Hello
packets every 30 seconds.
Set the poll interval
on the NBMA
interface
ospf timer poll
seconds
Optional
By default, poll packets are sent
every 120 seconds.
Set the dead time of
the neighboring
router on the interface
ospf timer dead
seconds
Optional
By default, the dead time for the
OSPF neighboring router on a
p2p or broadcast interface is 40
seconds and that for the OSPF
neighboring router on a p2mp or
NBMA interface is 120 seconds.
Set the interval at
which the router
retransmits an LSA to
the neighboring
router on the interface
ospf timer retransmit
interval
Optional
5 seconds by default.
 Note:
Do not set an LSA retransmission interval that is too short. Otherwise, unnecessary
retransmission will occur. LSA retransmission interval must be greater than the round
trip time of a packet between two routers.
4.7.3 Configuring the LSA transmission delay
Follow these steps to configure the LSA transmission delay: