in addition to the other post, there is a special case where both interfaces do not need to be on the same subnet, yet still can talk to each other. This setup uses IP unnumbered addressing for the BRI (or Dialer) interfaces. Check the following link for a sample configuration:
Configuring ISDN BRI Using the ip unnumbered Command
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...