R2511-HP MSR Router Series Layer 3 - IP Routing Configuration Guide(V5)
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• NBMA—When the link layer protocol is Frame Relay, ATM, or X.25, OSPF considers the network
type as NBMA by default.
• P2P—When the link layer protocol is PPP, LAPB, or HDLC, OSPF considers the network type as P2P
by default.
Follow these guidelines when you change the network type of an interface:
• When an NBMA network becomes fully meshed (any two routers in the network have a direct
virtual circuit in between), change the network type to broadcast to avoid manual configuration of
neighbors.
• If some routers in a broadcast network do not support multicasting, change the network type to
NBMA.
• An NBMA network must be fully meshed. If it is partially meshed, change the network type to P2MP
to simplify configuration and save costs.
• If a router on an NBMA network has only one neighbor, change the network type to P2P to save
costs.
Two broadcast-, NBMA-, P2MP-type interfaces can establish a neighbor relationship only when they are
on the same network segment.
Configuration prerequisites
Before you configure OSPF network types, complete the following tasks:
• Configure IP addresses for interfaces so neighboring nodes can reach each other at network layer.
• Enable OSPF.
Configuring the broadcast network type for an interface
Ste
p
Command
Remarks
1. Enter system view.
system-view N/A
2. Enter interface view.
interface interface-type
interface-number
N/A
3. Configure the OSPF network
type for the interface as
broadcast.
ospf network-type broadcast
By default, the network type of an
interface depends on the link layer
protocol.
4. Configure a router priority for
the interface.
ospf dr-priority priority
Optional.
The default router priority is 1.
Configuring the NBMA network type for an interface
After you configure the network type as NBMA, you must specify neighbors and their router priorities
because NBMA interfaces cannot find neighbors by broadcasting hello packets.
A router priority of 0 means the neighbor does not have the right for DR election. A router priority greater
than 0 means the neighbor has the right for DR election.