How to add Windows Defender Firewall ports (Network/Practice)

Article ID: 3231
Last updated: 10 Feb, 2022

The following ports must be open to allow communication between the server and client machines. These port changes should suffice for the majority of installations.

Server Side

Incoming Rule

  • DiscoveryService.exe Port 3838 (UDP)
  • Postgres.exe Port 5432 or 5433 (TCP)

Outgoing Rule

  • DiscoveryService.exe Port 6178 (TCP)
  • Postgres.exe Port 5432 or 5433 (TCP)

Note: If users on a Cloud Server installation type are unable to connect to the DB, please ask them to make sure that port 38476 is open on the router.

IMPORTANT: From version 4 of TaxCalc (November 2016) it is necessary to add the port 5433 (TCP) and 5432 (TCP) as Taxcalc has updated the version of PostgreSQL used. If you're unsure as to which port is being used, then please see steps below to assist. Any installation post 2020 will be using the port 5432 and TaxCalc will continue to do so, unless customised by the user or IT team to meet local environment variables.

Client Side

Incoming Rule

  • TaxCalcHub.exe Port 5432 or 5433 (TCP)

Outgoing Rule

  • TaxCalcHub.exe Port 5432 or 5433 (TCP)
  • TaxCalcHub.exe Port 6178 (TCP)

How to determine which PostgreSQL port is being used (5432 or 5433):

Select your Windows Start Button (bottom left) and type Discovery Response Editor

If the Discovery Response Editor does not appear in the Windows Start Menu. Please use the following path to locate the direct launcher: C:\Program Files (x86)\Acorah Software Products\TaxCalcDiscovery

Select the Discovery Response Editor launcher to open

Once the Discovery Response Editor opens, displayed in the screenshot below will be the port that the Postgres service is expecting.

Example of adding a firewall rule (inbound or outbound) – these steps will assist you with inputting the necessary rules to allow database communication between the server and client machine(s).

1) Select your Windows Start Button (bottom left) and type Firewall – select the following highlighted option:

2) Select Advanced Settings

3) Select Inbound Rules to add an incoming rule or Outbound Rules to add an outgoing rule.

4) Select New rule

5) Select Port

6) Select the appropriate rule type:

7) Type the necessary rule into the box for example:

8) Select Next – ensure that the each rule added to your firewall is set to Allow the connection (inbound and outbound)

9) Select Next ensure that Private is ticked

10) Select Next and name the rule as per the knowledge based article. For example:

11) Select Finish to complete and add the firewall rule.


  • By default PostgreSQL uses port 5432 or 5433 (TCP) (November 2016 onwards), although this can be customised.
  • The discovery service, that accepts multicast messages from clients to the server, listens on Port 3838 (UDP).
  • The discovery service on the server will then respond to the client on Port 6178 (TCP), outgoing from the server, incoming to the client.

For any further issues attempting to implement the firewall rules, please contact support.

Article ID: 3231
Last updated: 10 Feb, 2022
Revision: 4
Views: 1328
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