Ospf Route Control - 3Com 7757 Configuration Manual

Setting an NBMA
Neighbor
Setting the DR Priority
on an OSPF Interface

OSPF Route Control

n
After an interface has been configured with a new network type, the original
■
network type of the interface is removed automatically.
Note that, neighboring relationship can be established between two interfaces
■
configured as broadcast, NBMA, or P2MP only if the interfaces are on the same
network segment.
Some special configurations need to be done on an NBMA network. Since an
NBMA interface cannot discover the adjacent router by broadcasting Hello
packets, you must manually specify the IP address of the adjacent router for the
interface and whether the adjacent router has the right to vote.
Table 234 Set NBMA neighbor
Operation
Enter system view
Enter OSPF view
Set an NBMA neighbor
You can control the DR/BDR election on a broadcast or NBMA network by
configuring the DR priorities of interfaces.
Table 235 Set the DR priority on an OSPF interface
Operation
Enter system view
Enter interface view
Set the DR priority on the
OSPF interface
n
The DR priorities configured by the ospf dr-priority command and the peer
command have different purpose
The priority set with the ospf dr-priority command is used for actual DR
■
election.
The priority set with the peer command is used to indicate if a neighbor has
■
the right to vote. If you specify the priority to 0 when configuring a neighbor,
the local router will believe that the neighbor has no right to vote and sends no
Hello packet to it. This configuration can reduce the number of Hello packets
on the network during the election of DR and BDR. However, if the local router
is already a DR or BDR, it will send Hello packets to the neighbor whose DR
priority is 0 to establish the neighboring relationship.
Perform the following configurations to control the advertisement and reception
of the routing information discovered by OSPF and import routing information
discovered by other protocols.
Command
system-view
ospf [ process-id
[ router-id router-id ] ]
peer ip-address
[ dr-priority
dr-priority-value ]
Command
system-view
interface interface-type
interface-number
ospf dr-priority priority
OSPF Route Control 313
Description
-
Required
Required
By default, the priority for
the neighbor of an NBMA
interface is 1.
Description
-
Required
Optional
The default DR priority is
1.