Latest questions from the community.
With two dual-port Mellanox ConnectX-4 cards, a MikroTik SFP+ switch, 1 m OM4 patches and mixed 10G/25G transceivers from several vendors, one NIC port showed link UP but got no DHCP and could not route, 25G transceivers negotiated only 1G, and previously stable 10G links dropped intermittently…
Before deployment the poster asked for a certified or tested SFP28 DAC to connect an HPE FlexFabric 5950 with an SFP28 card to a dual-port Mellanox MCX4121A-ACAT (ConnectX-4 Lx), and for any documentation of that pairing. Hardware involved: HPE FlexFabric 5950, Mellanox MCX4121A-ACAT, SFP28 DAC…
We are handing a 100G circuit off to a core router through a leased optical transport system, and the port on our side refuses to come up. The same pair of modules links instantly on the bench, which is what makes this so irritating. Wedge100BF-32X (wedge100bf32x) running SONiC InnoLight…
Intel-branded servers witth a built-in ConnectX-3 (MT27500, ConnectX3-A1-WSP-QDR, firmware 2.36.5000, mlx4en 4.6, kernel 4.19.68) lost link when a QSFP-to-SFP+ adapter with an SFP+ transceiver replaced direct QSFP cabling: ethtool reported Link detected: no and speed Unknown!, port in ETH moe. The…
Home setup, everything in one rack. I want to connect the NAS to the switch faster than gigabit, but I don't want to run fiber: the distance is about five meters, a plain patch cord covers it. D-Link DGS-1250-28X switch, SFP+ ports free TerraMaster F4-424 Max NAS, copper RJ-45 port short Cat6a…
Small homelab, two second-hand switches and a drawer of optics collected over the years, most of which the hosts refuse because of the vendor code. Recoding has always been the blocker: a proper programmer sits around 369 USD, which is more than I paid for the switches, and the Ubiquiti SFP Wizard…
I do industrial installs, mostly Hirschmann switches in cabinets nobody wants to open twice. On the last couple of projects the optics were the line item that hurt: the switches expect Hirschmann-coded modules, and the original M-SFP parts cost several times an equivalent generic module, with lead…
The poster wanted to use a QSFP+ 40G-to-4x10G breakout cable on a two-port Mellanox ConnectX-3 Pro (MT27520, firmware 2.42.5044, PSID HP1370110017, MLNX OFED 4.6 on Debian 9.6) so each 10G leg could connect to a different switch, similar to what an Intel XL710 offers. SR-IOV virtual functions had…
On Debian 8.11 (kernel 3.16) the poster ran ethtool -m on a Mellanox MT26448 adapter to read optical diagnostics (TX/RX power, temperature, voltage, thresholds) and got Cannot get module EEPROM information: Input/output error. Hardware involved: Mellanox MT26448 ConnectX-2, SFP+ optic with DDM…
I want the ISP box out of the meter cupboard and the GPON line terminated straight on the router. It is a KPN-based line, fibre comes in on SC/APC, and the idea is to move the WAN from the Huawei ONT into the SFP+ cage of the UDM-Pro and keep exactly the VLAN 6 / PPPoE setup the ONT was running…
A DGX Spark with a ConnectX-7 NIC was connected to an existing 10G SFP+ optical network through an inexpensive QSFP-to-SFP+ adapter bought on AliExpress; neither DACs nor standard optical modules produced any link. The poster asked whether the setup could work at all and how to configure it…
We are moving the office uplinks from copper to fibre and the quote that came back has DrayTek-branded optics in every line. Before I start arguing about the difference against ordinary 10G modules I would like to know whether the hardware actually cares what sits in the cage, because the…
I do small business installs, and this one is a fibre service handed off on an ADVA FSP 150-GE102Pro. The customer wants the WAN terminated on their own router instead of the carrier box, so it has to land in the SFP+ cage of a MikroTik RB4011iGS+. Nobody told me what fibre the service actually…
A QSFP112 400G SR4 module in a ConnectX-7 (MCX755106AC-HEAT) with an MPO-12 Type-B cable showed module state Ready and data path DPActivated, but mlxlink --showmodule reported State = Disable, Supported Cable Speed = 0x00000000, Compliance = Unspecified/Undefined, Power Class 1.5 W (too low for…
We are wiring an FPGA capture card into an existing server and I am stuck at the very first step: the port simply never comes up. The setup: Mellanox MCX414-GCAT (ConnectX-4 EN, QSFP28, 50GbE capable) in the host FS Q-8LCA020 breakout AOC, QSFP+ on one end, eight LC ends on the other FPGA card on…
