RedHat Enterprise 7/CenOS 7 Firewall oneliners

Assuming you're using the default zone of "public" (you may need to temporarily disable selinux (setenforce 0)):


1. To allow everyone to access port 8080/tcp:

   firewall-cmd --zone=public --add-port=8080/tcp --permanent


2. Allow a server from the IPv4 address 10.20.30.40 to access this server on port 1234 over UDP:

firewall-cmd --zone=public --add-rich-rule='rule family="ipv4" source address="10.20.30.40/32" port port="1234" protocol="udp" accept' --permanent

CentOS 7 error: Connection 'wired connection 1' is not available on the device ens32 at this time.

This error is presented when attempting to bring up a network connection using nmcli. The connection name can be anything, of course.

There is a RedHat bug on this titled "RHEL 7 syslog shows failure related to network.service" bug #1079353.

There is no fix listed in the bug. I've seen this on a virtual machine, and the easiest work around was to delete the virtual machine's NIC, reboot, add a new NIC - reboot. After doing that, I deleted the new network connection using nmcli and applied the new device to the original connection profile I was attempting to use.