SFP not working after 3COM 2928 firmware update

[sbue]

Hi all,

I got multiple pairs of 3COM 2928 (3crbsg28hpwr93, JE007A-like) switches linked (but not stacked) via SPF+ (J9281B, DAC cable).

After upgrading the firmware from 5.20 1108P01 to 5.20 1519P03 I am no longer able to establish a connection over said SPF DAC cable.

Here's what the interface looked prior to the upgrade (CLI> display transceiver interface):

GigabitEthernet1/0/25 transceiver information:
Transceiver Type : STACK_SFP
Connector Type : COPPER
Wavelength(nm) : N/A
Transfer Distance(m) : 1(TP)
Digital Diagnostic Monitoring : NO
Vendor Name : Tyco Electronics
Ordering Name : N/A

Afterwards:

GigabitEthernet1/0/25 transceiver information:
Transceiver Type : STACK_SFP_PLUS
Connector Type : COPPER
Wavelength(nm) : N/A
Transfer Distance(m) : 1(TP)
Digital Diagnostic Monitoring : NO
Vendor Name : Tyco Electronics

What's irritating me the most are the syslog entries regarding the transceiver.
Pluggig it out and in before the update gave me:

Time/Date Source Level Digest Description
Dec 27 18:34:39:27 2018 IFNET Warning LINK UPDOWN GigabitEthernet1/0/25: link status is UP
Dec 27 18:34:32:250 2018 IFNET Warning LINK UPDOWN GigabitEthernet1/0/25: link status is DOWN

Doing the same after the update led to:

Time/Date Source Level Digest Description
Dec 27 17:31:37:574 2018 OPTMOD Warning MODULE_IN GigabitEthernet1/0/25: The transceiver is STACK_SFP_PLUS.  
Dec 27 17:23:38:511 2018 OPTMOD Warning MODULE_OUT GigabitEthernet1/0/25: The transceiver is absent.  

I would like to understand what I'm at before buying new, officially compatible transceivers.

So I'm wondering why "Source" changed to "OPTMOD". J9281B is copper based and not an "optical module".

Is there any tweak that allows me to use the old transceiver/cable?
It's clearly not a hardware but a software issue, as it was working with the older firmware (too old, shame on me).

Many thanks in advance! Please tell me if I should provide further information.

Best
Simon

[parnassus]

Funny, you're irritated...I'm totally surprised: how was it possible that a DAC Cable (which works at 10Gbps) was recognized by a SFP Slot (which works at 1Gbps)? the unsupported condition is not the actual one but the previous (working for you) one!

There is no HP OfficeConnect 1910 Switch series's model that is able to support DAC Cables or SFP+ Transceivers...so, eventually, the Software Upgrade you performed definitely fixed an abnormal condition your Switch was forced (not by you but by the hardware inserted and uncorrectly recongnized) to work with...

[sdide]

Hi,

Its all very strange.

The J9281B is a 10G Cobber SFP+ cable for Procurve switches.

The JE007A (OfficeConnect 1910-24G series, or 3com 2928 ) is a 24Ge RJ45 and 4 x SFP  1G ports.

Normally 10G containers (ports/interfaces) accepts 1G transceivers and downgrades accordingly, but 1G containers really doesn't eat 10G transceivers -  never.

So first off :   ----> Its not supposed to work <----

Surpringsingly it does. It might work electrically with the 10G SFP+, but its definately not supported - and I guess it never was. HPE probably fixed some issue on the port, or made the software check for things on the transceiver.

I would say things are after the upgrade - working as intended.
According to this  (manual) use:

2 x JD089B (and a normal CAT6 cable)  or
user 2 optical transceivers and a suitable fiberpatch cable.

Regards