D-Link xStack DGS-3610 Series User Manual

Chapter 28 OSPF Routing Protocol Configuration DGS-3610 Series Configuration Guide
28-12
 There is no ASBR in stub areas. In other words, the routes outside an autonomous
system cannot be transmitted in the area.
To configure the OSPF area parameters, execute the following commands in the routing
process configuration mode:
Command
Function
DGS-3610(config-router)#area area-id
authentication
Set plain-text authentication as the
authentication mode for the area
DGS-3610(config-router)#area area-id
authentication message-digest
Set MD5 authentication as the authentication
mode for the area
DGS-3610(config-router)#area area-id stub
[no-summary]
Set the area as a stub area
no-summary: Set the area as a stub area to
prevent the ABR between areas from sending
summary-LSAs to the stub area
DGS-3610(config-router)#area area-id
default-cost cost
Configure the cost of the default route sent to
the stub area
Note
For authentication configuration, you still need to configure the
authentication parameters at the interface. See ―Configuring the OSPF
Interface Parameters‖ section in this chapter. You must configure the stub
area on all the devices in the area. To configure a full stub area, you still
have to configure the full stub area parameters on the border device of the
stub area in addition to the basic configuration of stub area. You do not
need to change the configuration of other routers.
28.2.5 Configuring OSPF NSSA
The NSSA (Not-So-Stubby Area) is an expansion of the OSPF STUB area. The NSSA also
reduces the consumption of the resources of the routers by preventing the Category 5 LSA
(AS-external-LSA) from flooding the NSSA. However, unlike the STUB area, the NSSA can
inject some routes outside the autonomous region to the route selection area of the OSPF.
Through redistribution, the NSSA allows the external routes of autonomous system type 7 to
the NSSA. These external LSAs of type 7 will be converted into the LSAs of type 5 at the
border router of the NSSA and flooded to the entire autonomous system. During this process,
the external routes can be summarized and filtered.
You should pay attention to the following when you configure the NSSA:
 The backbone area cannot be configured as a NSSA, and the NSSA cannot be used as
the transmission area of the virtual links.
 To set an area as the NSSA, all the devices connected to the NSSA must be configured
with the NSSA attributes by using the area nssa command.

D-Link xStack DGS-3610 Series Specifications

General

Brand	D-Link
Model	xStack DGS-3610 Series
Category	Switch
Language	English