[tor-relays] [ARM] Connecting to another host's control port with ARM: Connection refused.

Hello, Tor community. Quick, possibly noobish question. I'd like to use my desktop and connect ARM (running on the desktop) to the control port of a server running Tor on the same LAN, but it's refusing the connection. I'm running /sudo -u tor arm -i 10.0.0.3:9051/, and it outputs:

robert@CPC-Arch:~$ sudo -u tor arm -i 10.0.0.3:9051 [sudo] password for robert: Connection refused. Is the ControlPort enabled?

I can connect to the control port from the same host fine, but when I try to do it from another host it fails. There must be something I'm missing. Hope you guys can help me. Thanks.

-Robert