Using 40GE QSFP to 4x 10GE SFP+ splitter cable

Today I was very frustrated when I connect a 40GE QSFP to 4x 10GE SFP+ splitter cable to a HPE FlexFabric 5700 48G 4XG 2QSFP+ switch (JG894A). I received the following message:

[HPE]%Jan 8 19:02:19:652 2011 HPE OPTMOD/4/MODULE_IN: FortyGigE1/0/54: The transceiver is STACK_QSFP_PLUS_4SFP_PLUS.

[HPE]%Jan 8 19:02:50:826 2011 HPE OPTMOD/3/TYPE_ERR: FortyGigE1/0/54: Transceiver type not supported!

First reaction: PANIC! The customer was waiting for delivery and now we had this problem… I looked at the transceiver information and the cable was shown correctly:

[HPE]dis transceiver int FortyGigE 1/0/54
FortyGigE1/0/54 transceiver information:
Transceiver Type : STACK_QSFP_PLUS_4SFP_PLUS
Connector Type : COPPER
Wavelength(nm) : N/A
Transfer Distance(m) : 5(STACK)
Digital Diagnostic Monitoring : NO
Vendor Name : HP
Ordering Name : JG331A

F**K… whats the problem? The distributor told me to just plug it in (I think it was a salesman, not a technician -.-) The offical product document also shows the supported transceiver/splitter-cables:

HPE FlexNetwork X240 40G QSFP+ to 4x10G SFP+ 1m Direct Attach Copper Splitter Cable JG329A
HPE FlexNetwork X240 40G QSFP+ to 4x10G SFP+ 3m Direct Attach Copper Splitter Cable JG330A
HPE FlexNetwork X240 40G QSFP+ to 4x10G SFP+ 5m Direct Attach Copper Splitter Cable JG331A

I googled the logmessages and topics about this cable but I couldn’t find any solution. I installed the new software image 5700-cmw710-system-r2432p01 (previous version 5700-cmw710-system-r2422p01) and made a reboot but the console shows again the “not supported” message. So I went to the interface and looked to the commands and I found something:

[HPE-FortyGigE1/0/54]using tengige
The interface FortyGigE1/0/54 will be deleted. Continue? [Y/N]:y
Reboot the member device to make the configuration take effect.
[HPE-FortyGigE1/0/54]save force
Validating file. Please wait…
Saved the current configuration to mainboard device successfully.
[HPE-FortyGigE1/0/54]quit
[HPE]quit
<HPE>reboot

after the reboot, the splitter cable was recognized and the transceiver error message doesn’t appear again. The “dis int brief” command shows also the four new interfaces:

interface Ten-GigabitEthernet1/0/54:1
#
interface Ten-GigabitEthernet1/0/54:2
#
interface Ten-GigabitEthernet1/0/54:3
#
interface Ten-GigabitEthernet1/0/54:4

After this I find an article at H3C to this command. It says “By default, a 40-GE interface is not split and operates as a single interface. The 10-GE breakout interfaces support the same configuration and attributes as common 10-GE interfaces, except that they are numbered differently. A 40-GE interface split into four 10-GE breakout interfaces must use a dedicated 1-to-4 cable.”

The interfaces are numbered from 1 to 4 but the cable has stickers from A to D:

I hope that I can help alot of people with this. From now on, Google will guide you to this article 😉 and when you don’t need this cable anymore, you can use it as a necklace:

NetworkDoge – “WOW SO MUCH CABLE” 😀

 

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