The architecture described places the ArcGIS Web Adaptors in a DMZ, acting as reverse proxies for the ArcGIS Enterprise components located on the internal network. For this configuration to function, the Web Adaptors must be able to forward incoming requests to the backend components. The ArcGIS Web Adaptor for Portal for ArcGIS communicates with the Portal component on its default HTTPS port, 7443. Similarly, the Web Adaptor for ArcGIS Server communicates with the ArcGIS Server component on its default HTTPS port, 6443. Therefore, the firewall between the DMZ and the internal network must permit traffic on these two ports.

B. 443 and 6443: Port 443 is for external traffic to the Web Adaptor, not for communication from the Web Adaptor to the internal network components.

C. 80 and 443: These are standard web ports for external access to the Web Adaptors, not for the required internal communication between the Web Adaptor and backend components.

D. 2443 and 6443: Port 2443 is not used by the core Portal for ArcGIS or ArcGIS Server components for this type of communication in a base deployment.

1. Esri ArcGIS Enterprise Documentation. "Ports used by ArcGIS Server." This document explicitly states that port 6443 is used for HTTPS communication and that "The ArcGIS Web Adaptor communicates with ArcGIS Server through this port."

Source: ArcGIS Enterprise 11.2 Documentation

ArcGIS Server > Reference > Ports used by ArcGIS Server.

2. Esri ArcGIS Enterprise Documentation. "Ports used by Portal for ArcGIS." This document specifies that port 7443 is used for HTTPS communication and notes

"The ArcGIS Web Adaptor communicates with Portal for ArcGIS through this port."

Source: ArcGIS Enterprise 11.2 Documentation

Portal for ArcGIS > Reference > Ports used by Portal for ArcGIS.

3. Esri ArcGIS Enterprise Documentation. "Using a reverse proxy server with ArcGIS Enterprise." This guide illustrates architectures where a reverse proxy (like the Web Adaptor in a DMZ) forwards requests to backend servers. The diagrams and text confirm that traffic is forwarded from the proxy to ArcGIS Server on port 6443 and to Portal for ArcGIS on port 7443.

Source: ArcGIS Enterprise 11.2 Documentation

Portal for ArcGIS > Administer > Security > Using a reverse proxy server with ArcGIS Enterprise.