I checked the DDWRT site, and I don't think your router is capable of running DDWRT. Could you try setting up Internet Connection Sharing on your main computer? I checked the internet and this might work, not an official guide though.
Open up the Control Panel, go to the Network and Sharing Centre. Click "Change Adapter Settings". Now right click on the Local Area Connection, click "Status" and then click "Details". Note down your current IPv4 address.
Right click the Local Area Connection again and hit Properties. Select "Internet Protocol Version 4" from the list, and click Properties. Click "Use the following IP Address" and input your current IPv4 address. For subnet mask, type in 255.255.255.0. Click OK.
Now, right click the "Local Area Connection 2" (It should be the one with the TAP-Win32 Adapter). Select Properties, then click Sharing. Tick 'Allow other network users to connect through this computer's Internet connection', and tick 'Allow other network users to control or disable the shared connection'
Now connect to our US-SurfingStreamingUDP server.
Go to your PS3 and open the Internet Connection Settings. Select Custom, then Wired Connection. When it asks for Operation Mode, select Auto-Detect. At IP Address settings, select Manual.
Now input your computer's IPv4 address at the Default Router, Primary DNS and Secondary DNS fields. Input 255.255.255.0 for the Subnet Mask. For IP Address, take your computer's IPv4 address and add one at the end, so if your computer is 192.168.1.3, type in 192.168.1.4
Save your settings, reboot your PS3 and see if you can connect to Netflix.