Crystal Server 2013: Cannot run report from outside our network

When my laptop is on our network, inside the firewall, and I access our Crystal Server by fully qualified domain name (http://server.mydomain.com:8080/BOE/CMC) I can run a report just fine.

However, when I attempt to access externally via IP address, I get the error in the screenshot below

(http://public.i.p.address:8080/BOE/CMC)

(http://xxx.xxx.xxx.xxx:8080/BOE/CMC)