A few days ago I added an Equallogic san and an additional esx host on my network. I am really close to having it all setup, but am scratching my head on this one.
On my 2nd esx host I have 4 total nics setup for iSCSI traffic. 2 ports on 1 card, 2 ports on another card. 1 set of ports goes to switch A, 1 set of ports goes to switch B.
Both switches are passing iscsi traffic to each other without issue. I've tested this by connecting 1 laptop to 1 switch, and another laptop to the other switch, and pinging each other's IP address.
In my networking setup for esx host, I cannot to get iSCSI to work if 2 specific ports (vmnic4/vmnic5) are active. I have to set both of those nics as standby or remove them for the host to recognize the SAN's LUN. As soon as I include them as active iSCSI no longer works for that host. I've double checked the config on the switch and all 4 switchports are configured the same. One thing that stick out, is if I look at the observed IP ranges for the nics, the 2 problem nics do not show the same subnet as the 2 working nics.