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c-Class 1Gb Enet Pass-Thru Module can't pass 100Mb?

Skip McDowell
Occasional Advisor

c-Class 1Gb Enet Pass-Thru Module can't pass 100Mb?

I'm setting up a c-Class BladeSystem in our test lab with 4 BL460c server blades using the 1Gb Enet Pass Thru Modules connected to a Cisco 4507 with all 100Mb switch ports. I'm not even getting a link light on the Pass Thru module ports but the Cisco switch ports have no problem when plugging another server in or even the c-Class iLO interface to them.

I know the NICs in the BL460c are multi-function and according to the HP Product Bulletin the Pass Thru module does a 1:1 pass thru so what gives?

Can the c-Class 1Gb Pass Thru module pass thru a 100Mb or even a 10Mb signal? The reason I threw in the 10Mb because I'm planning on setting up a SQL cluster and MS recommends the heartbeat NICs to be set to 10Mb half-duplex.

-Skip
7 REPLIES
David Claypool
Honored Contributor

Re: c-Class 1Gb Enet Pass-Thru Module can't pass 100Mb?

Microsoft's recommendation is strictly related to a heartbeat passed over a crossover cable and doesn't apply when a switch is involved.

As far as the pass-through, it passes through a 1Gb signal, not a 10/10/1000 signal.

Main page for the product: http://h18004.www1.hp.com/products/blades/components/ethernet/pass-thru/index.html

"Full Duplex 1G Ethernet only."

Specification tab: http://h18004.www1.hp.com/products/blades/components/ethernet/pass-thru/specifications.html

"Full duplex 1Gb per port (no auto-negotiation)"

Q&A tab: http://h18004.www1.hp.com/products/blades/components/ethernet/pass-thru/questionsanswers.html#a5

"Q5. Can the uplink ports be set to operate at any speed other than 1Gb?
A5. No, The 1Gb Ethernet Pass-Thru module does not auto negotiate and will not accept commands to operate at any uplink speed other than 1Gb."

From the QuickSpecs: http://h18004.www1.hp.com/products/quickspecs/12524_div/12524_div.html#Technical%20Specifications

"Network Transfer Rate / 1000 Base-TX (full-duplex) / Full Data Rate"


...not sure how it could be much clearer...
Skip McDowell
Occasional Advisor

Re: c-Class 1Gb Enet Pass-Thru Module can't pass 100Mb?


David-

Thanx for the response but you need to lose the 'tude. Our HP blade system account rep was unaware of this and, quoting from the latest HP Product Bulletin, "the c-Class 1Gb Ethernet Pass-Thru Module provides transparent, 1:1 port connectivity between the Server and an external switch." To me that implies that the module will "pass thru" any speed/duplex combination, especially seeing as to how the BLc server blade NICs are multi-function.

Maybe you could get them to edit the blurb in the HP Product Bulletin to read,"the c-Class 1Gb Ethernet Pass-Thru Module provides transparent, 1:1 port connectivity between the Server and an external switch, as long as it's 1Gb full duplex."

-Skip
sherwoodj
Occasional Visitor

Re: c-Class 1Gb Enet Pass-Thru Module can't pass 100Mb?

Skip- Did you find any work around to this problem? We have been facing the same issue and it seems that the only work around is adding another layer of switching (which seems like a waste of time and money).. Any other options that you have tried?
Pasi Koistinen
Occasional Contributor

Re: c-Class 1Gb Enet Pass-Thru Module can't pass 100Mb?

Hi.

C-class Pass-Thrue modules can ONLY communicate with 1Gb link.

10 / 100 Mbs are not supprted in Pass-Thrue modules, only in switch.
Graeme Dods
Occasional Visitor

Re: c-Class 1Gb Enet Pass-Thru Module can't pass 100Mb?

Skip,

The NICs in the blades are only 1Gb and don't do 10/100Mb. So even if the pass-thru module were capable of passing through 10/100Mb traffic you'd still only get 1Gb available via external connections.
Skip McDowell
Occasional Advisor

Re: c-Class 1Gb Enet Pass-Thru Module can't pass 100Mb?


Grame-

According to the latest HP Product Bulletin, NICs 1 & 2 in all c-Class server blades are the Multifunction NC373i. The Dual Port NIC in the BL480c & BL685c is a NC326i which is indeed a 1 Gb NIC and functions as NICs 3 & 4. So unless HP changed the meaning of multifunction the same time they changed the meaning of transparent pass-thru, then NICs 1 & 2 in all c-Class server blades should work at 10/100/1000 speeds.

-Skip
Graeme Dods
Occasional Visitor

Re: c-Class 1Gb Enet Pass-Thru Module can't pass 100Mb?

Skip,

There's no change of definition as there's no standard definition for "Multifunction" as far as I'm aware. You may be thinking of "multispeed" or "autosensing" or whatever vague (and often inaccurate) word some marketing guys have come up with to describe the capabilities of the latest piece of hardware.

In this case multifunction means having the ability to handle TOE (TCP/IP Offload Engine), accelerated iSCSI and RDMA (Remote Direct Memory Access). In other words it can - help take the network processing load off the server, act as an iSCSI initiator for iSCSI storage and can move memory between machines rapidly (usually in large server clusters).

The only mention of 10/100Mb is for the iLO, but that goes through the Onboard Administrator and not through the interconnect bays.

It's all there in the QuickSpecs, but as is fairly common for QuickSpecs the information can get lost amongst the noise. I used to proof-read QuickSpecs for one of HP's product lines that I knew inside out so I know how hard it can be to get the right information across.

Cheers,

Graeme