The software described in this documentation is either no longer supported or is in extended support.
Oracle recommends that you upgrade to a current supported release. br_netfilter Module

The Platform CLI checks whether the br_netfilter module is loaded and exits if it is not available. This module is required to enable transparent masquerading and to facilitate Virtual Extensible LAN (VxLAN) traffic for communication between Kubernetes pods across the cluster. If you need to check whether it is loaded, run:

$ sudo lsmod|grep br_netfilter
br_netfilter           24576  0 
bridge                155648  2 br_netfilter,ebtable_broute

If you see the output similar to shown, the br_netfilter module is loaded. Kernel modules are usually loaded as they are needed, and it is unlikely that you need to load this module manually. If necessary, you can load the module manually and add it as a permanent module by running:

$ sudo modprobe br_netfilter
$ sudo sh -c 'echo "br_netfilter" > /etc/modules-load.d/br_netfilter.conf'