When you use autoscaling, all nodes have the same Name tag, which makes ec2dns useless for those. You should think of a notation to specify an index when nodes are ordered by launch date, then by, let's say, instance ID, as it might be possible to have the same timestamp. As you use it in your own example, -n suffix would be a good idea for indexing, where n is the 1-based index.
When you use autoscaling, all nodes have the same Name tag, which makes ec2dns useless for those. You should think of a notation to specify an index when nodes are ordered by launch date, then by, let's say, instance ID, as it might be possible to have the same timestamp. As you use it in your own example,
-nsuffix would be a good idea for indexing, wherenis the1-based index.