To begin with the last question: The status as observed is in fact normal behaviour.
Spoofing is in other words "faked up". An interface that's inactive normally goes down which also causes all routes running over it to be dropped from the routing table. This status was implemented to allow dialers to keep their static routes also when the dialer was inactive. Check with the command "show dialer" to see if there is any undesired calling action.
Use an access-list to allow traffic to activate the dialer.
We are pleased to announce availability of Beta software for 16.6.3. 16.6.3 will be the second rebuild on the 16.6 release train targeted towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are looking for early feedback from custome...