H3C S9500 Series Operation Manual page 267

Operation Manual – Routing Protocol
H3C S9500 Series Routing Switches
physical interfaces, you can also configure various interface parameters on this link,
such as hello timer.
The "logic channel" means that the routers running OSPF between two ABRs only take
the role of packet forwarding (the destination addresses of the protocol packets are not
these routers, so these packets are transparent to them and the routers forward them
as common IP packets). The routing information is directly transmitted between the two
ABRs. The routing information herein refers to the Type-3 LSAs generated by the ABRs,
for which the synchronization mode of the routers in the area will not be changed.
Perform the following configuration in OSPF area view.
Table 4-30 Configure an OSPF virtual link
Create and configure a virtual
link
Remove the created virtual link
By default, the value of hello seconds is 10 seconds, the value of retransmit seconds is
5 seconds, the value of trans-delay seconds is 1 second, and the value of dead
seconds is 40 seconds.
4.2.21 Configuring Stub Area of OSPF
Stub areas are some special areas, in which the ABRs do not propagate the learned
external routes of the AS.
The stub area is an optional configuration attribute, but not every area conforms to the
configuration condition. Generally, stub areas, located at the AS boundaries, are those
non-backbone areas with only one ABR. Even if this area has multiple ABRs, no virtual
links are established between these ABRs.
To ensure that the routes to the destinations outside the AS are still reachable, the ABR
in this area will generate a default route (0.0.0.0) and advertise it to the non-ABR
routers in the area.
Pay attention to the following items when configuring a stub area:
The backbone area cannot be configured to be the stub area and the virtual link
cannot pass through the stub area.
If you want to configure an area to be the stub area, then all the routers in this area
should be configured with this attribute.
No ASBR can exist in a stub area. In other words, the external routes of the AS
cannot be propagated in the stub area.
Perform the following configuration in OSPF area view.
Operation Command
vlink-peer router-id [ hello seconds | retransmit
seconds | trans-delay seconds | dead seconds |
simple password | md5 keyid key ]*
undo vlink-peer router-id
4-25
Chapter 4 OSPF Configuration