We have created an separate network for our Eqaullogic SAN traffic to our VMware 4.0 environment. The network consists of 2 cisco 2960G switches (SanSwitch1 & SanSwitch2) that have ports 20-24 configured as etherchannels between the two switches. These switches are configured for multi-path I/O. Each of the three host servers (Dell 2950) have a total of 4 NICS installed. Nic1 & Nic2 are connected to SanSwitch1 and SanSwitch2, respectively. The Equallogic SAN has active/standby controllers. Controller A has 3 ports port 1&2 connect to SanSwich1; port 3 connects to SanSwitch2; The standby controller B also has a total of 3 ports. Ports 1$2 are connected to SanSwitch2 and port 3 is connected to SanSwich1. In VMware each of the hosts are configured with multiple vswitches. Vswitch0 is for the production network, Vswitch1 for the SAN network, and Vswitch2 is set to connect to our secure network. Vswitch1 consists of a Port group called Guest SAN Network and that port group has the two nics assigned. Everything seemed to be working well. Or so I thought. I introduced a forth server to build a small test environment, loaded an eval version of vmware. I setup a separate network on an independent switch to mimic our Production environment, But the I created connections to the SAN based on the same settings as the production servers. No connection to the secure network was neccessary. Again, everything looked good up to the point I introduced a copy of our domain controller into the test environment and received a warning that the computer name existed on the network. Now I am trying to figure out how production traffic is getting onto the SAN network. The guests on the Vm ESXi servers all use the SAN to boot. I can only guess that somehow the traffic is getting directed on one of the guest servers.