Dynamic addressing on a private net

[MrWolfe]

I have 2 machines connected together via a private subnet (10.0.0.0), with the server also connected to the internet via a second ethernet card. I'm running Ubuntu, and I'm able to set up internet sharing, which sets up a NAT'ed private net with its own DHCP server. I want to share the internet connection from time to time to allow the client machine OS to be updated. The problem is that Synergy does not seem to be able to support dynamic addressing. When I try to share the internet connection, Synergy stops working because it's set up for manual addressing (server on 10.0.0.1, client on 10.0.0.2). To summarise the setup, the server has two ethernet cards, Eth0 connects to the internet via a LAN and Eth1 connects directly to the client machine. I can set up internet sharing on the server, but that creates a private network with a virtual router with its own DHCP server and the subnet address can't be configured easily. Is there any way to get Synergy to work over a link with dynamic addresses?