Hi @Anonymous ,
You could consider using aggregate rollup monitors for your network interfaces, for more information see:
Aggregate Monitors
https://video2.skills-academy.com/en-us/previous-versions/system-center/system-center-2012-R2/hh457599(v=sc.12)
You can also check my blog post about it over here:
https://thesystemcenterblog.com/2020/01/26/scom-alert-basics/#3_Aggregate_Rollup_Monitors
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Best regards,
Leon