[quagga-users 14853] Re: ospf route-map

On 01/11/2017 15:16, William Herrin wrote:
> On Wed, Nov 1, 2017 at 7:59 AM, Mark Coetser <mark-ajVlV48O6s/[email protected] 
> <mailto:mark-ajVlV48O6s/[email protected]>> wrote:
> 
>     OK i have a working ospf setup between multiple routers including
>     some mikrotiks. OSPF works fine but now I have been trying to create
>     an access list to block a quagga router from advertising a ospf
>     learned subnet and for some reason I cant seem to get this right....
> 
>     so I have router A with a local subnet of 192.168.60.0/24
>     <http://192.168.60.0/24> that is connected to router B which in turn
>     is connected to router C, I am trying to get router B to stop
>     advertising 192.168.60.0/24 <http://192.168.60.0/24> to router C
> 
> 
> Hi Mark,
> 
> If I understand what you're asking (I might not) then OSPF doesn't work 
> that way. Filtering routes only works on the router first introducing 
> ("redistributing") the route in to OSPF. That's router A in your 
> example. Once in OSPF the route can't be conditionally removed somewhere 
> else with any configuration.
> 
> You can filter the route if you redistribute it from OSPF to some other 
> protocol such as BGP. But you can't filter it within OSPF.

Hi Bill

OK that sort of makes sense, now I just need to figure out how to 
accomplish what I am trying to achieve......

The thing is router B still need to access the 192.168.60.0/24 network 
but router C shouldnt have that route and I need OSPF because there are 
multiple connections between each of the routers via different ISPs and 
I am running GRE tunnels across each of the different links.

Thank you,

Mark Adrian Coetser