<span style="font-family: Calibri"><span style="font-size: small">Key words: </span></span>

<span style="font-family: Calibri"><span style="font-size: small">Cisco UCS blades provide a new “Appliance” fabric interconnect port type that can be used to direct-connect IP SAN storage to the fabric interconnects. Here are a few tips learned from a recent project connecting an EMC VNX array to Cisco UCS B-Series blades using 10GB iSCSI:</span></span>
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	<li><span style="font-size: small">·</span>         <span style="font-size: small"><span style="font-family: Calibri">Designate two separate, isolated (non-routed) VLANs to be used for iSCSI traffic, one for each fabric interconnect:</span></span>
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	<li><span style="font-size: small">o</span>   <span style="font-size: small"><span style="font-family: Calibri">Name the VLANs something simple and self-documenting like iSCSI-A and iSCSI-B</span></span></li>
	<li><span style="font-size: small">o</span>   <span style="font-size: small"><span style="font-family: Calibri">Assign a private IP address range to each VLAN. As a best practice, these should not conflict with any other IP addresses used inside the corporate network</span></span></li>
	<li><span style="font-size: small">o</span>   <span style="font-size: small"><span style="font-family: Calibri">Create the VLANs on the network tab in UCS Manager</span></span></li>
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	<li><span style="font-size: small">·</span>         <span style="font-size: small"><span style="font-family: Calibri">Connect the storage array to the fabric interconnects using two 10GB links per storage processor.  Connect each SP to both fabric interconnects and configure the ports on the fabric interconnect as “Appliance” ports</span></span></li>
	<li><span style="font-size: small">·</span>         <span style="font-size: small"><span style="font-family: Calibri">Assign the appliance ports on fabric interconnect A to VLAN iSCSI-A and the appliance ports on fabric interconnect B to VLAN iSCSI-B</span></span></li>
	<li><span style="font-size: small">·</span>         <span style="font-size: small"><span style="font-family: Calibri">Configure the IP addresses on the SP ports. The ports connected to fabric interconnect A get an IP address in the range assigned to iSCSI-A and the ports connected to fabric B get an IP address in the range assigned to iSCSI-B</span></span></li>
	<li><span style="font-size: small">·</span>         <span style="font-size: small"><span style="font-family: Calibri">Add two virtual interfaces in the host service profiles, one for iSCSI-A and one for iSCSI-B. Assign these to the appropriate VLAN</span></span></li>
	<li><span style="font-size: small">·</span>         <span style="font-size: small"><span style="font-family: Calibri">Configure the host OS for iSCSI, assigning an IP address on the iSCSI-A VLAN for one interface and on iSCSI-B for the other.  In the iSCSI configuration specify the appropriate Storage Processor IP addresses initiator ports for each VLAN</span></span></li>
	<li><span style="font-size: small">·</span>         <span style="font-size: small"><span style="font-family: Calibri">Here’s the key to success: The VLANs <span style="text-decoration: underline">must exist</span> on the upstream switches the fabric interconnects use to interface with the rest of the network. The upstream switches are in the critical path for network traffic, even traffic between storage and servers in the UCS environment. This means that <em>having redundant upstream switches is essential for high-availability</em>, as <span style="text-decoration: underline">network traffic will not flow inside the UCS</span> if the external uplink switches go down!</span></span></li>
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