Can't access dashboards of subdomain

My current site is http://www.marksgray.com and I’d like to add ip.marksgray.com and immigration.marksgray.com, but cannot get this working. I have followed all the instructions I was able to find, I can see all the sites listed, but cannot access the dashboard for the subsites. I’ve been on the phone with network solutions all morning and have gotten nowhere, other than them blaming it on wordpress.