Start memcached using another port
The default port for accessing memcached is 11211 and is automatically configured as an allowed port for remote connections. You can change it using these commands:
$ echo export MEMCACHED_PORT_NUMBER=11212 | sudo tee -a /opt/bitnami/scripts/memcached-env.sh
In this example, 11211 is your original Memcached port and 11212 (example) is the new port to use. Once done, restart the memcached server for the change to take effect.
$ sudo /opt/bitnami/ctlscript.sh restart