Hey, It's just a wild guess, but did you tried: ``` protocol ospf [v2|v3] <name> { ... interface <interface pattern> [instance <num>] { check link <switch>; }; .. } ``` I'm not sure if or what difference it would make if you add your prefix to a static protocol and set the `check link` there, too. Again, it's just a wild guess... Good luck, Bernd On 28.04.24 11:30 AM, chan alfie wrote:

Hi, community

I have create a loopback interface on linux and assign 4 subnets on it.

``` ip link add dev lo235 type dummy ip link set lo235 up ip addr add 10.23.5.1/30 dev lo235 ip addr add 10.23.5.5/30 dev lo235 ip addr add 10.23.5.9/30 dev lo235 ip addr add 10.23.5.13/30 dev lo235 ```

stubnet <prefix> { summary;}; is used on an originator routers(r235) ospf area, and it indeed propagted the summary prefix instead of subnets, here is the config:

r235: ``` area 10.23.0.0 { ... stubnet 10.23.5.0/28 { summary; } ... } ```

r235: ``` show ospf state ... router 10.23.0.5 distance 0 ... stubnet 10.23.5.0/28 metric 10 ... ```

but when I shutdown the lo235 or delete all of the subnets, the 10.23.5.0/28 is still advertised by r235.

r235 ``` ip link set lo235 down or ip addr del 10.23.5.1/30 dev lo235 ip addr del 10.23.5.5/30 dev lo235 ip addr del 10.23.5.9/30 dev lo235 ip addr del 10.23.5.13/30 dev lo235 ```

r235 ``` bird> show ospf state router 10.23.0.5 distance 0 ... stubnet 10.23.5.0/28 metric 10 ```

How to make ospf advertise stubnet base on the interface/subnet state, (interface up/down, subnets existed or not)?

By the way, networks{} clause works as expected. When the subnet of originator router is dismiss, the ABR's networks will take effect(disappear of appear).