3COM 2928 (HP 1910) firmware update 1519P03 stops accepting a J9281B 10G DAC in its 1G SFP slots
2
Several pairs of 3COM 2928 switches (JE007A-like, HP 1910-24G family) were linked over J9281B SFP+ DACs. After upgrading from 5.20 1108P01 to 5.20 1519P03 the links no longer came up. Before the update display transceiver interface showed STACK_SFP / Tyco Electronics and simple LINK UPDOWN events; afterwards the type changed to STACK_SFP_PLUS and the log source became OPTMOD with MODULE_IN/MODULE_OUT messages. The poster asked why a copper cable was now treated as an optical module and whether a tweak could restore the old behaviour.
- Hardware: 3COM 2928 (3CRBSG28HPWR93), HP 1910-24G JE007A
- Transceivers: HP J9281B SFP+ DAC, HP JD089B RJ45 SFP
- Form factor: SFP, SFP+, DAC
Symptoms / messages:
link lost after firmware upgrade
OPTMOD MODULE_IN: The transceiver is STACK_SFP_PLUS
Comments 2
The 1910/2928 only has 1G SFP slots; a 10G DAC was never supported and the old firmware simply mis-detected it. The new release checks the transceiver properly, so the behaviour is as intended.
Use two JD089B 1G RJ45 SFPs with a Cat6 cable or a pair of 1G optical transceivers with a fibre patch cord instead.