[c-nsp] OSPF NSSA question

[Ivan Pepelnjak]

Hi!

You gave me a good reason to finally test this command and document what it
does and how it's used in a hub-and-spoke environment:

http://wiki.nil.com/OSPF_flooding_filters_in_hub-and-spoke_environment

It's exactly what's needed to solve the original problem (but of course you
need a static default route on the spoke routers as they lose all OSPF
information).

Best regards
Ivan
 
http://www.ioshints.info/about
http://blog.ioshints.info/ 

> -----Original Message-----
> From: Ruben Alvarez [mailto:raa at opusnet.com] 
> Sent: Wednesday, July 22, 2009 5:17 PM
> To: 'Mateusz Blaszczyk'; 'Ivan Pepelnjak'
> Cc: cisco-nsp at puck.nether.net
> Subject: RE: [c-nsp] OSPF NSSA question
> 
> I'm not sure filtering 'out' would work.  Three routers all 
> have one interface, each connecting to the ABR (which has 
> four interfaces, three to the routers in area 1 and one in 
> area 0.)  If I'm filtering out, The ABR wouldn't know which 
> routes are on each of the three routers.  Right?  The three 
> routers have thousands of single host routes spread out over 
> each router.  The ABR knows which router has each host and 
> summarizes to area 0.
> 
> -----Original Message-----
> From: Mateusz Blaszczyk [mailto:blahu77 at gmail.com]
> Sent: Wednesday, July 22, 2009 1:10 AM
> To: Ivan Pepelnjak
> Cc: Ruben Alvarez; cisco-nsp at puck.nether.net
> Subject: Re: [c-nsp] OSPF NSSA question
> 
> 2009/7/22 Ivan Pepelnjak <ip at ioshints.info>:
> > You're probably looking for the "ip ospf database-filter 
> all out" command.
> 
> And how the summary LSA with 0/0 would get to the spoke 
> router if that is filtered out?
> (assuming nssa scenario in OP's hub n'spoke topology)
> 
> Best Regards,
> 
> -mat
> 
>