Separate network for iSCSI

Posted on 2010-08-18
Last Modified: 2013-11-14
Hi Experts,

Have a question regarding setting up a iSCSI connection to a SAN from a Windows 2003/2008 server using MS iSCSI. We currently have it setup so that from the server one NIC connects to the main VLAN - 192.168.2.X and the other NIC connects to a SAN VLAN - 192.168.12.X

The SAN is connected to the same switch to which these NICs terminate. Is this the right way to set up the iSCSI connection or is there a better way? We don't notice too many issues on the network but if there were a better way to do it then we can try. We do have spare Cisco Catalyst 3560 lying around but we can't purchase a dedicated iSCSI HBA. Do we need to connect the SAN on a completely different switch with only NICs from the servers attached to it? If so how would routing work? We are not looking into redundancy currently but to see if speeds can be increased on the SAN. TIA
Question by:abhijitm00
  • 2
  • 2

Accepted Solution

jimmyray7 earned 333 total points
ID: 33469748
The SAN should be on it's own segment.  Ideally a separate switch, at minimum, a separate VLAN.  With a dedicated switch you can do some iSCSI optimizations like jumbo frames, etc.  Speed increase would depend on the current switch's load, but it should be better.  A separate switch also makes troubleshooting easier, as you immediately know which network the problem stems from.

Author Comment

ID: 33469945
Thanks for getting back Jimmy but how would you physically connect the cables. I would assume you would have a cable from the SAN ( going to the Cisco switch. Another cable from the server's second NIC ( going into it as well. How would they talk though. What would you put under the gateway for the server NIC? Also what configuration would need to go onto the switch? Please correct me if my assumptions are wrong. We are using Cisco Catalyst 3560G switches

Assisted Solution

jimmyray7 earned 333 total points
ID: 33470051
NIC1 - data network- would plug into the existing switch.
NIC2 - SAN - would plug into the second switch (SAN only).

The two switches should be completely separate.  The SAN switch should be isolated without any connections anywhere else.

The data network config wouldn't change.  The SAN NIC shouldn't need a gateway, as there is no outside access.  Just an IP and subnet mask.

Let me see what I can dig up regarding the cisco iscsi config.

Author Comment

ID: 33474539
Thanks Jimmy. So I would disconnect my SAN NIC from my server and plug into the new switch put in the IP and subnet and then another NIC from the SAN with IP and subnet connecting to this new switch. How would the new switch need to be configured in terms of IP and VLAN? Would I set it up with an IP address and subnet as well, would I need to add VLAN info or anything else you can think of? Again the servers would be using the MS iSCSI software initiator

I appreciate you looking up the cisco iscsi config.

Assisted Solution

johnemyers earned 167 total points
ID: 33764087
On the Iscsi Switch
1. enable PORT FAST on the switch ports. (Brings ports online quick and turns off STP)
2. Lable the ports with descriptions ( Server a, b , SAN A ,B )
3.  Optional   Setup a Management IP for inband management  ( If you have Vlans on network the management Vlan is allowed to all devices)
If no Management VLAN the console or direct cable to switch is the only way to manage the switch.


Featured Post

Optimizing Cloud Backup for Low Bandwidth

With cloud storage prices going down a growing number of SMBs start to use it for backup storage. Unfortunately, business data volume rarely fits the average Internet speed. This article provides an overview of main Internet speed challenges and reveals backup best practices.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

How to update Firmware and Bios in Dell Equalogic PS6000 Arrays and Hard Disks firmware update.
Concerto Cloud Services, a provider of fully managed private, public and hybrid cloud solutions, announced today it was named to the 20 Coolest Cloud Infrastructure Vendors Of The 2017 Cloud  (…
This video teaches viewers how to encrypt an external drive that requires a password to read and edit the drive. All tasks are done in Disk Utility. Plug in the external drive you wish to encrypt: Make sure all previous data on the drive has been …
This tutorial will walk an individual through the process of installing the necessary services and then configuring a Windows Server 2012 system as an iSCSI target. To install the necessary roles, go to Server Manager, and select Add Roles and Featu…

820 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question