[j-nsp] OSPF Area Problem with Directly Connected Vlan not being Advertised

[Chuck Anderson]

On Sat, May 22, 2010 at 02:09:47PM -0400, Jose Madrid wrote:
> I am setting up some new devices at a physically separate data center
> and am seeing some weird OSPF behavior.  In order to get the default
> route injected, I setup this new DC as a stub area (area 0.0.0.1) and

>  For some reason, although this vlan is turned on and configured, the
> /29 in use wont be advertised into OSPF.  In order to make it work, I
> was forced to add the specific sub-interface for vlan 50 into my OSPF
> config and was wondering if you guys could tell me how/why I can
> overcome this behavior.  The reason this is a problem is that now

Area 0.0.0.1 is a Stub area, but using policies to export 
Direct/Static into OSPF causes those routes to appear as AS Externals 
and turns the router into an ASBR.  Stub areas can't have AS Externals 
(Type 5 LSAs).  The reason it works when you put the VLAN interface 
into protocols ospf is because then OSPF treats it as an internal 
route (Type 1/2/3 LSAs) rather than an external route (Type 5).

You can solve this by reconfiguring area 0.0.0.1 to be an NSSA area.  
The external routes will then be advertised via Type 7 LSAs, and the 
ABR will convert them to Type 5 LSAs injected into the backbone area.

On the ABR(s):

area 0.0.0.1 {
    nssa {
    	default-lsa default-metric 40;
	summaries;
    }

On the interior router (J2320):

area 0.0.0.1 {
    nssa;