How To Improve Security Using The Built-In Firewall - Linksys EA4500 V3 Manual

Click the MAC Filtering tab.
Select Enabled next to MAC Filters. Click Yes when asked whether you want to continue. Select Allow access for ONLY the listed MAC addresses.
Click Add MAC Address. Enter the MAC address into the MAC Filter List and click Apply.

How to improve security using the built-in firewall

By default, the firewall settings in your router work well in most home environments. You don't need to make changes. The SPI (Stateful Packet Inspection) firewall is enabled by
default, and anonymous Internet requests and IDENT requests are filtered by default. All web filters are disabled, because enabling them may cause problems for sites that depend on
ActiveX controls, Java, or cookies.
If you decide to change your firewall settings, log in to Linksys Smart Wi-Fi. (See "How to connect to Linksys Smart Wi-Fi" on page 7.) Under Router Settings, click
Security. The Security page will open to the Firewall tab.
You can now change the following settings:
TIP
For more descriptions of each setting, click Help at the top of the
screen.