I'm getting these info entries in my router logs and I am able to suppress them by not logging info events. The events are related to l2tp/IPsec tunnels which are working properly as are the OSPF routes that rely on them. I'm not understanding why the output interface is unknown. Perhaps because the interface is dynamic? I'm just curious if this is something to be concerned about, possibly indicative a an issue or poor practice that I'm not aware of. Thanks in advance for your input.

16:07:39 firewall,info input: in:ether1 out:(unknown 0), connection-state:established src-mac cc:2d:e0:d6:08:xx, proto 50, xxx.yyy.zzz.19->xxx.yyy.zzz.223, len 124
16:07:39 firewall,info input: in:ether1 out:(unknown 0), connection-state:established proto UDP, xxx.yyy.zzz.19:1701->x.y.z.223:1701, len 78

How you know on what interface the packet go out, before the packet cross the routing facility?