UPDATE: If you have upgraded to DSM 5.0 check Block authorized people from access your Synology NAS DSM 5.0
Once your Synology is accessible from the internet, some people will try to hack your password and access your NAS. Synology offers a service to block people’s IP address when they fail to log in after a specified number of attempts. This service will prevent them from trying again from the same IP.
Here is how you set up this functionality:
3. Click on Auto Block in the Network section of the control panel:
4. Click on Enable Auto Block and select the number of login attempts within the period specified. For example, if you chose 5 and 5, the person trying to access your nas will be able to try to login 5 times in 5 minutes, if he/she does not succeed the IP address will be blocked and will not be able to try to login again.
If you select Enable block expiration the IP address will be unblocked after the number of days you specify in the text box below.
<img” src=”https://synoguide.files.wordpress.com/2013/12/ipautoblock-menu.jpg” alt=ipautoblock menu” width=”=300″ height=”37″ />
And selecting the tab Block List:
The same can be done for the Allow list, that is the list of IP’s that you don’t want to block; for example your static address.