I installed a server with SBS 2011 Essentials on it. I disabled the router(Linksys E2000) from doing DHCP and enabled it on the server. Was having an issue with getting internet access. I ended up manually setting up the computers with static IP's and that seemed to solve the computers connected by wire and even a laptop that connected over wireless. The next issue was portable devices connecting to the wireless were not getting internet connection. I ended up turning the DHCP, on the router, on again and devices were working again(I know I can't leave both running). I've done this setup a few times, but never with sbs 2011 essentials, and have not had a problem. Am I missing setting something up on the server or the router?