How do I configure an alert to cover multiple IP ranges?

Hello,

Sorry for the newbie question, I'm just looking into how I can set up a single 'node down' email alert for a range of IP addresses.....

So say I have 10 IP ranges, class A 10.128.120, 10.128.112. 10.128.128 and so on - I want an alert for all the devices within these IP's if a node goes down. 

Would I just set the monitor as follows:

Or is there a way to say 'if Condition A is met and ANY of Condition B is true = send alert?

I want to avoid having to create individual alerts for every single IP range if possible.

Thanks for any replies.