Is the DI-624's firewall secure enough?

[Kyrano]

My two computers connect to my DI-624 wirelessly. Both run Trend Micro antivirus. My question is do I need to run a software firewall if my DI-624's firewall is active? What kind of protection would the software firewall give me over the hardware firewall (if any)?

Currently my router is set to NOT broadcast its SSID, use WPA-PSK, and use MAC filtering. The firewall is active, but I have not added any "Firewall Rules". I also changed the original SSID and admin password. The computers never operate outside of my wireless LAN, so protection while "on the road" is not a concern.

 

[skyking]

The "firewall" in the router blocks anonymous requests from the WAN, and that is about it. It has a few tools to recognize common attacks, but the biggest benefit you get is just being hooked up to a NAT device, a router.
If someone sends some malicious stuff at your external IP, your router would not know which computer to send it to on the LAN. It then "Drops it on the floor", or discards it.
Note that this is only working one way, on things trying to get into your network. Any application, spyware, trojan or remote control can always connect outbound. The default behavior on outgoing requests is to "allow all".
A software firewall does not automatically allow outbound traffic. You need to train it to allow the common protocols.
This can be very handy, since a trojan or other nasty, or anything designed to "phone home" will get blocked by default, and you will be notified.
It is up to you how secure you want to be. A router's "firewall" will not block malicious code in a webpage that you request, for example. You ask for it, you get it.