Quickbooks Multi-User Mode Setup

https://community.intuit.com/articles/1021211-firewall-and-internet-security-settings-for-updates-and-network-access

On the Server:

1. Click the Start menu and type firewall.
2. Click on Windows Firewall.
3. On the right-hand side, click on Advanced Settings.
4. Click on Inbound Rules to highlight it.
5. Right-click on Inbound Rules and select New Rule.
6. Select Port and click Next.
7. Make sure TCP is selected and type in the following ports for your year of QuickBooks: (if you have multiple years of QuickBooks installed or will be using, you will need to add each years ports as well in this format: 8019, XXXXX, XXXXX, XXXXX, XXXXX).
   • QuickBooks 2016: 8019, 56726, 55368-55372
   • QuickBooks 2015: 8019, 56725, 55363-55367
   • QuickBooks 2014: 8019, 56724, 55358-55362
   • QuickBooks 2013: 8019, 56723, 55353-55357
8. Click Next and make sure Allow the Connection is selected, then click Next again.
9. Click Next again and give the rule a name, such as QBPorts. Click Finish when done.
10. Repeat the steps above for the Outbound Rules (for step 4 inbound rules, choose Outbound Rules).
11. Try opening QuickBooks again in multi-user mode or over your network to see if the issue has been resolved.