content_image/1009293.jpg
Figure 3-17 shows an overview of the iSCSI implementation in the SAN Volume Controller. 

<img src='content_image/1009293.jpg'>

Both onboard Ethernet ports of a SAN Volume Controller node can be configured for iSCSI. For each instance of an iSCSI target node (that is, each SAN Volume Controller node), you can define two IPv4 and two IPv6 addresses or iSCSI network portals: 

GLYPH<SM590000> If the optional 10 Gbps Ethernet feature is installed, you can use them for iSCSI traffic. 

GLYPH<SM590000> All node types that can run SAN Volume Controller V6.1 or later can use the iSCSI feature. 

GLYPH<SM590000> Generally, enable jumbo frames in your iSCSI storage network. 

GLYPH<SM590000> iSCSI IP addresses can be configured for one or more nodes. 

GLYPH<SM590000> iSCSI Simple Name Server (iSNS) addresses can be configured in the SAN Volume Controller. 

GLYPH<SM590000> Decide whether you implement authentication for the host to SAN Volume Controller iSCSI communication. The SAN Volume Controller supports the Challenge Handshake Authentication Protocol (CHAP) authentication methods for iSCSI. 

## 3.7.1 iSCSI protocol 

iSCSI connectivity is a software feature that is provided by the SAN Volume Controller code. The iSCSI protocol is a block-level protocol that encapsulates SCSI commands into Transmission Control Protocol/Internet Protocol (TCP/IP) packets. Therefore, iSCSI uses IP network rather than requiring the Fibre Channel infrastructure. The iSCSI standard is defined by Request For Comments (RFC) 3720: 

https://tools.ietf.org/html/rfc3720 

An introduction to the workings of iSCSI protocol can be found in iSCSI Implementation and Best Practices on IBM Storwize Storage Systems , SG24-8327. 

