[quagga-users 14579] only advertise network when internal IF is up?

Hi,

In my setup I have two routers (lets say R1 and R2) connected to two 
uplinks of one large ISP.

Both of my routers where advertising my prefix and the ISP sends return 
packets to R1 and in failure of R1 switches to R2.

Lastly I had an issue with the internal NIC of R1, so iBGP addressed 
outgoing packets via R2, but since the external NIC of R1 was 
operational the router itself advertised the prefix and so return 
packets from the ISP were send to nowhere on R1.


I'm using the network statement in BGP and in Zebra have a Null Route 
for the prefix. My thought to solve this explicit issue is to set a 
route for the prefix via internal IF, so when the NIC is down R1 doesn't 
advertise any networks.

Not really sure if this is really the way how to solve situations like 
these? I also read about bgp conditional advertisement, but perhaps this 
is a bit oversized for a small network?


Any ideas? Or is a route via internal just fine?


Thanks,

Michael