I want www.glassespeople.com to run at a vps from hostgator, and http://forums.glassespeople.com to run at aother shared web hosting from hostgator also, and do not use redirect to achieve this. We all know if we deal redirect not well, it is very bad for our sub domain seo.
2 steps, first we set forum.glassespeople.com to an ip of the new shared hosting from vps:
Home » DNS Functions » Edit DNS Zone
forum 14400 in a 18.104.22.168, here 22.214.171.124 is your new shared hosting ip.
second step, go to your new shared hosting cpanel, first an addon domain: glassespeople.com, then add sub domain name: