Need Help with adsl modem and WR840n


I am using an adsl connection with tplink VC220-G3u. I want to use a tplink WR840n for all the client

My main issue is the modem i have looses all the config at random times, when power goes off, when its been too long on etc.

Is it possible to keep the modem as default since when the power goes it reverts to factory settings anyway and use WR840n for handling DHCP, mac filtering etc with different ip segments ? Modems default ip is and lets say i want to use WR840 with

Pls know that i have no prior knowledge about openwrt and i am trying to learn in my own environment

Thanks in advance

How do you expect us to know your ISP's requirements (as in what settings need to be done on the 'modem' before it works again) or the details about your proprietary VC220-G3u (does it reset to modem mode/ PPPoE pass-through or router mode)? In general, defective hardware -and a device randomly forgetting its configuration is defective- need replacing, working around it rarely leads to satisfaction.

Also be aware that all but rev 4 of the tl-wr840n are below minimum system requirements for OpenWrt (and rev 4 will be after the upcoming release), making it unsuitable to begin with.