default gateway on iSCSI network?

Phil Begriffenfeld

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Feb 22, 2008, 12:30:06 PM2/22/08

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Microsoft says to configure a Default Gateway on the private (iSCSI)
NIC of iSCSI hosts. For example, the whitepaper "Deploying IP SANs with
the Microsoft iSCSI Architecture :
http://www.viglen.co.uk/storagegroup/pdfs/Microsoft_Deploying_iSCSI_SAN-July2004.pdf

has an example of a "basic iSCSI" network, with:

Target IP: 10.10.0.5/8
Target's default gateway: 10.10.0.1
Group IP: 10.10.0.10

Host IP: 10.10.0.20/8
Host's default gateway: 10.10.0.1

Does anyone know why the Host/Client needs a default gateway pointing to
what appears to be an unused IP (10.10.0.1) on the iSCSI network?

This creates a problem for me, since I have a second NIC in the
Host/Client, which is connected to the public Internet, so that public
NIC needs a Default Gateway too. And Microsoft has numerous documents
saying "don't use two default gateways". Indeed, having the default
gateway of 10.10.0.1 assigned on the iSCSI NIC breaks Internet
connectivity for the Host.

Thanks for any clarification of the private-side Default Gateway!

-Phil

moojit

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Feb 23, 2008, 6:38:51 PM2/23/08

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"Phil Begriffenfeld" <Phil.Begr...@specialgreen.com> wrote in message
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Microsoft does not require this.

Moojit

Phil Begriffenfeld

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Feb 24, 2008, 10:03:01 AM2/24/08

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Thatks, Moojit. I had wondered why the whitepaper had said that. It
only says, when setting up the client/host:
"iii. Assign a default gateway to enable servers to access volumes on
the storage array (10.10.0.1)". Odd.

I thought perhaps this was to support installations where the client is
net-booting from a MS-Windows target (?). I do know that I have working
iSCSI SANs with no default gateway configured on the iSCSI/SAN NIC, but
those are using NetApp's target.

moojit

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Feb 24, 2008, 10:39:59 AM2/24/08

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"Phil Begriffenfeld" <Phil.Begr...@specialgreen.com> wrote in message

news:13s31p7...@corp.supernews.com...

Like any application, the IP parameters configured on your NIC are a 'don't
care' to Microsoft's iSCSI Initiator. In fact, DHCP will work too but not
recommended for storage solutions since you don't want your IP to change.

For a Boot-From-SAN (BFS) configuration, a standard NIC will not work. You
will need a Qlogic iSCSI HBA to perform this functionality. The HBA's PCI
Option ROM will attach to the iSCSI storage during POST.

Moojit

stevem...@gmail.com

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Feb 25, 2008, 9:55:53 AM2/25/08

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Moojit wrote in message:

> For aBoot-From-SAN(BFS) configuration, a standard NIC will not work. You

> will need a Qlogic iSCSI HBA to perform this functionality. The HBA's PCI
> Option ROM will attach to the iSCSI storage during POST.
>
> Moojit

Moojit - a standard NIC certainly will work (for iSCSI boot), as
evidenced by solutions available today form emBoot and others - and
this is fully supported by Microsoft.

Regards,
Steve Marfisi
emBoot Inc.
www.emboot.com

moojit

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Feb 25, 2008, 10:32:26 AM2/25/08

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<stevem...@gmail.com> wrote in message
news:034e362a-f9ed-4064...@h25g2000hsf.googlegroups.com...

I wasn't aware of this solution, thanks.

www.moojit.net