I have a single subnet with multiple physical servers in a single domain (call it Dom1). One of the servers is Windows 2008 EE with Hyper-V and I have multiple guest OS's. Two are individual servers with their own domains (Dom2 and Dom3). Another is a virtual XP box that is part of Dom1. I have enabled the Link-Layer stuff in Group Policy on W2K8 (the Hyper-V host and the virtual servers). All other servers are W2K3. The DNS of each domain has a conditional forward to the DNS of the other domains. I can ping and access all network resources from any machine -- physical or virtual. However, the virtual servers can only see virtual servers and the physical host server in Network Places; Dom2 can see the host server in Dom1 and all of Dom3 and Dom3 can see the host server in Dom1 and all of Dom2. The W2K3 physical servers in Dom1 can only see Dom1. The physical Hyper-V host can see all of Dom1, Dom2, and Dom3. So something is not traversing Hyper-V to make Dom2 and Dom3 visible to Dom1 and vice versa. The Hyper-V host has only a single adapter, so it supports both the host partition and the virtual external network. The network has only TCP/IP and DNS and does not do WINS or LMHOSTS or HOSTS. Does anyone have suggestions on what to do to allow Dom1 to see Dom2 and Dom3 and vice versa?