Greetings to all. I apologize for my English not very good
I have a virtualized iredmail server, version 1.6.2 that I have mounted on both debian 11 and ubuntu 20, it has openldap and sogo. I need to use to authenticate another service, a nextcloud, the iredmail ldap.

From the same iredmail I check with a localhost nmap and port 389 is open and it is verified and the salpd service is running. The problem is that when I nmap it from another server or computer on the same network, it doesn't show me that port 389 and when I try to configure it from nextcloud of course it gives me an error.

Additionally, the firewall that controls the network, have the respective permissions and policies to allow that iredmail server to communicate on port 389, without restrictions.

I come before you so that you guide me to see what I should do to see from other computers that open ldap port 389 and use it for nextcloud authentication