After enduring some pretty severe issues related to the onboard NIC and replacing with matching NIC Realtek cards and discovering that the Large Send Offload properties had to be disabled for the card to work properly, my Hyper-V supports all the RDP and remote situations it should (I am running on an SBS 2011 domain). But I am having trouble now with SQL Server clients not recognizing their server counterparts. There are three SQL servers running on the network (all SQL 2008 R2 - one standard, one enterprise and one developer). SQL Browser is enabled on all machines. I do not have the router configured to allows TCP 1433, but the domain is wide open to that port on all the firewalls. When I first implemented the solution using the single onboard NIC, I did not have this problem but I have run out of ideas as to how to make that port open throughout the network so that the SQL Server browsing (UDP 1434) can function between the servers and the virtuals. The non-virtual machines on the network can exchange information over these ports without issue. The virtuals can see each other and remote into each other but cannot recognize each other through the standard SQL ports. The regular machines can also not see the virtual versions of SQL. Pinging works without issue between all machines virtual or non virtual. I also noticed that the address leases originally recognized one of the virtuals on two IP addresses before I rebooted the machine and after I had disabled Large Send Offloads on that machine. I don't think that applies but it seemed odd. The other oddity is that one of the vituals still sees a LAN connection that no longer exists on the network (I disabled it on the virtual). The Hyper-V two NICs run on two separate IP addresses and one is virtualized with no IPv4 or IPv6 properties. I don't have a full understanding of the VLAN configuration nor of the MAC options on the virtual settings so I have them set for the default. What is causing the virtuals to be blocked from using the TCP 1433 and UDP 1434? (Could be a SQL Question but seems to me to be a network issue because it only applies to the virtuals)R, J

I would post this to the Virtual Server forum: http://social.technet.microsoft.com/Forums/en-us/virtualserver/threads. The fact that your non-virtual machines can browse the SQL servers, the v.machines cannot, and the fact that all the machines (V and non-V) can ping each other, all point to an issue either with the 'guest' o/s firewalls or the Hypervisor.