I have an OS X Server set up as a VPN server. The problem is, when I connect my iPhone to the server with my username and password, my laptop is disconnected. Then when I reconnect my laptop, my iPhone is disconnected. I haven't changed anything in the server configuration. Multiple users accounts can connect fine, but the same user can't have any more than one device connected without the server kicking them off. Any ideas?
You're most likely connecting both devices from the same public IP (behind NAT). If this is the case, you'll need to try your phone's cellular connection or use PPTP. You may have to configure the VPN gateway to use PPTP and forward the correct ports through your firewall/router.