Web Connections Fail With "Proxy Server Is Refusing Connections" Error on RHEL8

When connecting to web targets through PrivX on Red Hat Enterprise Linux 8 (RHEL 8), the browser displays "proxy does not allow connections" or a similar error message.

This issue may be associated to an incompatibility between Docker CE and RHEL 8's firewalld configuration (additional info here).

Potential Solution

RHEL8 firewalld and docker-ce are not natively compatible with each other, so Docker's network bridge (docker0) may be blocked by firewalld on RHEL 8. To address this, update firewall rules and restart the necessary services as follows:

firewall-cmd --permanent --zone=trusted --add-interface=docker0
service privx-carrier stop
service docker stop
service firewalld restart
service docker start
service privx-carrier start

After applying these changes, attempt the web connection again through PrivX.