I just read this for LYNC EDGE SERVER :
Two interfaces required, either one 2-port 1 Gbps NIC or two 1-port 1 Gbps NICs.
So I guess one is for internal LAN and one is for the DMZ.
1. Is it really necessary to have 2 NICs ?
2. Does the DMZ nic has to be able to access the internet ? and if so how do I do this on eg a DLINK DFL-160 (if I try it with my laptop and connect the lancable to the LAN and my laptop to the DMZ I cannot access the internet at this moment)