#2 you can copy/paste into Network Solar -> Bulk Upload option and have them be ICMP only nodes so you get up/down status
#1 another option is to use custom properties as a grouping element. Is there something unique or in common on these IP's? Meaning customerA, customerB etc.
Thank Brandon for your reply. Sorry for the delay
In fact the interfaces I am trying to group are simply a sort of workaround to monitor BGP IPs (without using UnDP OID).
For that I created a new set of Devices (ICPM poll only) named Node-x-BGP and kept them in a group. So whenever a BGP peer Interface stops responding, I can see this in the Group color alerts. It's Ok for me with this solution without SNMP/OID polling.