[nsp] OSPF NSSA

[Andrew Fort]

On 11/02/2004 6:23 PM, John Pang wrote:

>Hi Stephen and Mustafa,
>
>Thanks alot for your advice and info.
>
>I tried out Mustafa's method of putting R4's loopback
>into Area 1 and R1 is now able to see 2 paths to R4.
>:)
>
>Just curious but is putting the loopback into an Area
>a standard procedure? Is this behaviour standard for
>OSPF or is it due to the way Cisco IOSes operate?
>
>Previously I used to do redistribute connected to
>inject the loopback IP address into OSPF. How is this
>different from manually specifying the loopback IP
>address as a member of the area?
>
>Once again, many thanks for the kind advice and
>assistance.
>  
>

Using the network command causes the router to add the loopback address 
as a 'stub host' network on its router (type-2) LSA   If the NSSA area 
is the same as the area in which you've placed the loopback, the routers 
in the NSSA will see the route for the loopback

Using a redistribute statement causes the router to produce an 
AS-External (type-5) LSA, which will be seen everywhere throughout the 
network, except, in the NSSA area.

-afort