I’m having an odd issue. I have a QM8790, MCP7H50-H IB splitter cables, and 2 hosts with MT4123 (single port HDR100) HCAs. All have latest firmware installed on switch and HCAs. For some reason, only the host with cable “1” connects. Other cable, “2”, polls. I’ve swapped cables, hosts, tested with several cables. Only cable “1” of the splitter cable works. The other doesn’t. What is going on?
Here’s some more details of cable “2” (blue tab):
mlxlink -d mlx5_0
State : Polling
Physical state : ETH_AN_FSM_ENABLE
Speed : N/A
Width : N/A
FEC : N/A
Loopback Mode : No Loopback
Auto Negotiation : ON
Enabled Link Speed : 0x00000075 (HDR,EDR,FDR,QDR,SDR)
Supported Cable Speed : 0x0000007f (HDR,EDR,FDR,FDR10,QDR,DDR,SDR)
Status Opcode : 2
Group Opcode : PHY FW
Recommendation : Auto-negotiation no partner detected.
Thank you for posting your inquiry on the NVIDIA Developer Forum - Infrastructure and Networking - Section.
For both links of the Y-cable to function, you need to make sure that the switch is configured for split_mode.
The QM8790 is an unmanaged switch. For configuring split_mode on this switch, please follow the procedure described in the follow link → Using mlxconfig - NVIDIA Docs
You only need to set the switch to split_mode. After that the switch will auto-sense the cable and will activate the 2nd link.
Thank you and regards,
~NVIDIA Networking Technical Support
This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.