DNS doesn't matter if your using IP addresses, nor does the gateway if your using a local net proxy.
You seem "in the know".
So far, I've only been able to solo mine other SHA-256 coins with a cube by using BFG Miner and the --http-port #### option.
Is it even possible to use stratum proxy for solo mining?
Also, I've tried just using the cube by itself but it won't communicate with the wallet by setting the "Pool ports" to the rpcport in the wallet .conf file. Any suggestions? (I've probably asked this question about 3-5 times on this thread and once in its own thread, but people just said "point the cube at the wallet" which obviously so far has not worked.)