Is it required to open ports for localhost apps using that port on same server? I mean not extra connections are made from external servers..
for example i have installed memcached
service which requires a port on its settings(port 11211 for example) for the service delivery. Do I need any trust rule for that port to add in my firewalld to get it working for other local services and applications like php?
memcached
from the loopback interface (127.0.0.1)?