Note: Because there is a wide variety of software and hardware firewalls, we can only provide general information here. If you need help configuring your particular firewall, please consult your firewall's documentation.
In multi-user environments, QuickBooks uses the Internet protocol TCP/IP for data communication. If your company's network is protected by a firewall, you may need to reconfigure your firewall software to allow QuickBooks to communicate using TCP/IP.
You can configure most firewall software to give access to specific programs. To give QuickBooks access, configure your firewall software as shown in the table for these QuickBooks programs:
(Incoming and Outgoing traffic)
If you receive errors while in multi-user mode, you can search for the error online at the
QuickBooks Support Site.
You can contact Support by using Access Support Resources,
or you can review Troubleshooting multi-user problems.
About multi-user QuickBooks