Disabling Firewalld on recently updated CentOS 7 server
I have spent much longer than I expected figuring out why I could not login to my server using ssh on a recently updated CentOS server.
It turns out on CentOS 7 the default firewall Iptables is replaced by Firewalld. The issue that I experienced meant that 2 firewalls were enabled that did not work well with each other.
To avoid that the different firewall services influence each other, run only one of them on a RHEL host, and disable the other services.
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