I don't believe you need to be changing anything in the LW advanced>Network interface option.

You may have already done a port forwarding previously for that particular computer. I guess you could delete that setting & redo. Keep in mind also, if you forward a port, only do it for one computer. Any other computer on the network that's port forwarded will need a different port number. eg: port forward 6346 for one computer, 64049 for another, etc.

But if you're using more than one LW or p2p program at the same time, this might be what's over-whelming the router.

netgear do support UPnP so port forwarding might not be necessary. If you're connected & don't see a brick wall then perhaps either UPnP or port forwarding you did was fine. To enable UPnP on your device, see the UPnP section here Connection problems? Check here first! (click on link). PF or UPnP, whichever one works for you & works reliably for you. BTW have you checked to see if there's any firmware update for your netgear?