One of the reasons we "stongly" recommend that you use a different pair of subnets for pairs of SP ports (SPA0/SPPB0, SPA1/SPB1, SPA2/SPB2, SPA3/SPB3), is that on some operating systems where the hosts have two or more NIC's, all NIC's will log into all ports from both NIC's if everything is on the same subnet. Then you could be eigth paths per NIC and 16 total paths (with two NIC's per host) per host - you would start to overload the array iSCSI ports if you had a lot of hosts and they were all active at the same time. Plus, each port on the array would have two Host initiators logging into the same SP port - not sure how your failover software would react under that condition.  glen
We have a bunch (10) citrix xenservers connected to a CX4-120 via iSCSI connection.  Last night we had one iSCSI port resetting and basically all the citrix servers lost 1 path. I am new to iSCSI SAN topologies and found that all the citrix server initiators and the corresponding iSCSI ports on both SPs are on the SAME SUBNET (I am working with the network team to correct this situation). I did some research and found a primus emc156408 which says its not recommended to have all the initiators and FE ports on the same subnet and this might be the reason for the FE port to reset.  So my question is what exactly happens to make the FE port to reset in case of a single subnet configuration.  Thanks, Sri
Problem with Host iSCSI initiators and SP ports on same subnet