If I understand correctly, going from your reply to my comment: you have two WAN uplinks, each with a router, you have bought a double-uplink firewall to manage both WANs, your ISP has told you to put the two routers into transparent mode, you have done this for one of them, and it works. If it works, you should be able to surf the Internet using that one. If you turn off the one that works and you cannot surf any more, then you have proved you have a problem with the second one, which is a DG834.
The usual name for transparent mode is "bridged mode", and that is the name used by Netgear. The Netgear site seems to find that putting the equipment into bridged mode is so easy that it doesn't need any explanation, so hopefully you'll be able to take it from there.