Configuring Nbma Neighbors For Ospf; Setting The Interface Priority For Dr Election - 3Com 8800 Configuration Manual

3Com Switch 8800 Configuration Guide
Table 19-17 Configure a network type for an OSPF interface
Configure the network type on the interface
Restore the default network type of the
OSPF interface
By default, OSPF determines the network type based on the link layer type. After the
interface has been configured with a new network type, the original network type of the
interface is removed automatically.

19.2.12 Configuring NBMA Neighbors for OSPF

For an NBMA network, some special configurations are required. Since an NBMA
interface on the network cannot discover the adjacent router through broadcasting
Hello packets, you must manually specify an IP address for the adjacent router for the
interface, and specify whether the adjacent router is eligible for election.
Perform the following configuration in OSPF view.
Table 19-18 Configure the NBMA neighbors for OSPF
Configure the NBMA neighbors for OSPF
Remove the configured NBMA neighbors
By default, the preference for NBMA neighbor is 1.

19.2.13 Setting the Interface Priority for DR Election

On a broadcast or NBMA network, a designated router (DR) and a backup designated
router (BDR) must be elected.
The priority of a router interface determines the qualification of the interface in DR
election. The router with the priority of 0 cannot be elected as the DR or BDR.
DR is not designated manually. Instead, it is elected by all the routers on the segment.
Routers with the priorities larger than 0 in the network are eligible "candidates". Votes
are hello packets. Each router writes the expected DR in the packet and sends it to all
the other routers on the segment. If two routers attached to the same segment
concurrently declare themselves to be the DR, choose the one with higher priority. If the
priorities are the same, choose the one with greater router ID. If the priority of a router is
0, it will not be elected as DR or BDR.
Operation
Operation
19-18
Chapter 19 OSPF Configuration
Command
ospf network-type { broadcast |
nbma | p2mp | p2p }
undo ospf network-type
Command
peer ip-address [
dr-priority-number ]
undo peer ip-address
dr-priority