You would need to assign a unique IP addres (new) to the iSOE iface since this is a totally different interface.  Think of it as two different interfaces. 1) Find out the Hardware MAC Address for the Hardware iSCSI interface. The iSCSI offload MAC address will be one higher than the actual MAC address of the Ethernet NIC.  Since we are using eth1: #ifconfig eth1 | grep HW eth1 Link encap:Ethernet  HWaddr 00:22:19:5C:F2:FE Look in the ifaces directory to find the MAC address of the iSOE. #ls /var/lib/iscsi/ifaces/ bnx2i.00:00:00:00:00:00 bnx2i.00:22:19:5c:f2:fd bnx2i.00:22:19:5c:f2:ff Or #iscsiadm -m iface The iSCSI offload iface for eth1 in this example is bnx2i.00:22:19:5c:f2:ff 2) Now set the IP Address of the Hardware iSCSI interface. Note: In order to use a DHCP-assigned address, set the iface IP address to 0.0.0.0. #iscsiadm -m iface -I bnx2i.00:22:19:5c:f2:ff -o update -n iface.ipaddress -v 157.210.10.2 bnx2i.00:22:19:5c:f2:ff updated. 3) Verify the IP address of the iSCSI iface. #cat /var/lib/iscsi/ifaces/bnx2i.00:22:19:5c:f2:ff "# BEGIN RECORD 2.0-871 iface.iscsi_ifacename = bnx2i.00:22:19:5c:f2:ff iface.ipaddress = 157.210.10.2 iface.hwaddress = 00:22:19:5c:f2:ff iface.transport_name = bnx2i "# END RECORD Or #iscsiadm –m iface default tcp,,,, iser iser,,,, bnx2i.00:22:19:5c:f2:ff bnx2i,00:22:19:5c:f2:ff,157.210.10.2,, bnx2i.00:00:00:00:00:00 bnx2i,00:00:00:00:00:00,,, 4) (Optional) configure a subnet mask to the iface iscsiadm -m iface -I -o update -n iface.subnet_mask -v  This link has information on configuring iSOE (For RedHat) and performace information en.community.dell.com/.../download.aspx Regarding performance, generally speaking: Applications with small I/O sizes, like Web servers and database servers, iSOE technology can provide higher bandwidth and lower processor utilization than a software initiator. Applications with I/O sizes greater than or equal to 4 KB, such as data backup, iSOE can provide increased bandwidth and reduced processor utilization.
I am trying to optimize iscsi Equallogic SAN and was trying to configure Broadcom BCM57840 adapter to be in iSOE mode. I have question around assigning an IP to iSOE interface via iscsiadm the Dell Documentation say to execute below command to assign a ip to iSOE. iscsiadm -m iface -I -o update -n iface.ipaddress -v    However say i have interface eh0 and its ip is 10.3.10.140 so my question is should be i assigning new un-used ip to this iSOE interface ? And what benefit interms of performance do I get if use iSOE .Just to let know, I em doing this in Redhat 6.6 linux using HIT kit from dell. Thanks in Advance for any help on this.  
Configuring BCM57840 adapter in iSOE mode