Configuring A Virtual Link; Configuring Ospf Network Types - HP 4800G Series Configuration Manual

It is required to use the nssa command on all the routers attached to an NSSA area.
Using the default-cost command only takes effect on the ABR/ASBR of an NSSA area.

Configuring a Virtual Link

Non-backbone areas exchange routing information via the backbone area. Therefore, connectivity
between the backbone and non-backbone areas and within the backbone itself must be maintained.
If necessary physical links are not available for this connectivity maintenance, you can configure virtual
links to solve it.
Follow these steps to configure a virtual link:
To do...
Enter system view
Enter OSPF view
Enter area view
Configure a virtual
link

Configuring OSPF Network Types

OSPF classifies networks into four types: broadcast, NBMA, P2MP, and P2P, upon the link layer
protocol.
You can change the network type of an interface as needed. For example:
When an NBMA network becomes fully meshed through address mapping, namely, when any two
routers in the network have a direct virtual link in between, you can change the network type to
broadcast, without manually configuring the neighbors.
When some routers in the broadcast network do not support multicast, you can change the network
type to NBMA.
An NBMA network is fully meshed, which means any two routers in the NBMA network have a
direct virtual link for communication. If direct connections are not available between some routers,
the type of interfaces associated should be configured as P2MP, or as P2P for interfaces with only
one neighbor.
If two interfaces on a link are both configured as the broadcast, NBMA or P2MP type, they cannot
establish a neighbor relationship unless they are on the same network segment.
Use the command...
system-view
ospf [ process-id | router-id router-id |
vpn-instance instance-name ] *
area area-id
vlink-peer router-id [ hello seconds |
retransmit seconds | trans-delay
seconds | dead seconds | simple
[ plain | cipher ] password | { md5 |
hmac-md5 } key-id [ plain | cipher ]
password ] *
1-24
Remarks
—
—
—
Required
You need to configure this
command on both ends of a
virtual link.
Note that hello and dead
intervals must be identical on
both ends of the virtual link.