PiAlert without WAN access

For those of you who know of PiAlert or similar projects/forks like NetAlertX, do you know of any that can run without WAN access?

I just got PiAlert running the other day and noticed that it does not update correctly unless it has access to WAN which seems odd, since it's basically just running arp commands within internal IP ranges over specified interfaces.

Edit: Looks like I was just able to modify one function to return a hardcoded value to resolve the need to connect to WAN