CentOS memcached listen on localhost only

By default the memcached daemon listens on any interface and might be accessible from the internet. You can test this by running:

# netstat -an|grep 11211
tcp        0      0 0.0.0.0:11211             0.0.0.0:*                   LISTEN      
udp        0      0 0.0.0.0:11211             0.0.0.0:*

To secure that, edit the file in /etc/sysconfig/memcached and add to the OPTIONS line:

OPTIONS="-l 127.0.0.1"

And restart the service:

# /etc/init.d/memcached restart
Stopping memcached:                                        [  OK  ]
Starting memcached:                                        [  OK  ]

Have a new try on looking for the listening interface ports:

# netstat -an|grep 11211
tcp        0      0 127.0.0.1:11211             0.0.0.0:*                   LISTEN      
udp        0      0 127.0.0.1:11211             0.0.0.0:*

That is the result you want.