Thanks StealthDad, I figured it out by plugging in the individual subnet ips and adjusting my magacoin.conf accordingly. Now I have a different problem: I'm getting periodic "json_rpc_call failed, retry after 30 seconds" errors. It'll hash fairly well for a few minutes, then give me the error, then hash again, error, and so on.

Any thoughts?

EDIT: fixed!
I had the wrong final digit in the subnet; all is working well now.