DP 23.4 Home page not rendering - firewall issue?

Hi,

We have a new installation of DP 23.4:

  • RHEL 8.8 Cell Manager
  • RHEL 8.8 Reporting Server

When in the GUI, I go to Home page, but it does not render the GUI at all, no error, just a blank GUI grey blank page, i.e. not white page. When I turn off the firewall on CM, the Home page renders straight away on it's white page. So this suggests to me the firewall is the problem on the CM. I've allowed what I thought was all the ports for the Home page to work, but it's not working:

  • -A IN_public_allow -p tcp -m multiport --dports 80,443,5555,7116,8443,5432,7112 -m conntrack --ctstate NEW -j ACCEPT

What am I missing, checking other DP servers we have in other environments, they follow the same port set. The problem I have is the full iptables in /etc/sysconfig/iptables is massive. The environment I am supported was built by someone else, they have lots of rules, but no others for those ports.

Is there a "normal" firewall connection which would be expected to be allowed, that might be disabled on my system, which is stopping the home page rendering up with the firewall turned on?

Any help or advice gratefully received.

Cheers,

Andy