Alert when failover link is active

You can take your cloned copy and basically modify the autodiscovered filter so it ONLY contains your Loopback0 interface and that can be a dedicated "snmp64_loopback" (or whatever name you want) DataSource. You can then setup global thresholds on this new DataSource which will only apply to Loopbacks. You can still keep the original snmp64_if for primary and other ports with it's own separate thresholds.