Popular discussions about programming, compatibility and testing of optical transceivers.
On an Accton Wedge100BF-32x the ONLP call onlpsfpeepromread returned QSFP EEPROM data with alternating bytes skipped, so vendor strings appeared with every other symbol missing; the same transceiver read correctly on an Accton AS7312-54x. The vendor name FINISAR CORP appeared at the wrong offset…
Contradicting MikroTik's documented advice to force 1G full duplex when using 1G optics in SFP+ ports, a Netpower Lite 7R linked to an RBFTC11 only with auto-negotiation (forced 1G gave link up but zero received packets), while the same Netpower to a CRS328-4C-20S-4S+ had heavy packet loss and FCS…
An open hardware/firmware project to read and write the EEPROM inside SFP and SFP+ modules so their capailities and vendor origin can be inspected and modified. It uses an RP2040 microcontroller and exposes a USB Mass Storage interface. The project is a work in progress and does not yet document…
Monitoring reported packet loss toward an ESXi iSCSI host; on the Dell S4810 (FTOS 9.11(2.6)) the interface TenGigabitEthernet 0/37 showed the warning Non-qualified pluggable media present, SFP+ type is 10GBASE-CU2M because a non-Dell DAC was used. The link was up with normal traffic (about 16…
The poster tried a Mellanox MFA2P10-Axxx 25G SFP28 AOC between a MikroTik switch and a Supermicro server with an Intel X722 (ixl driver) under pfSense. The cable linked fine switch-to-switch but on the X722 ifconfig -vvvm showed the module recognised (10GBase-SFI, 1000Base-KX listed) yet no carrier…
The poster had free thrid-party SFP/SFP+ samples that worked on Extreme switches and asked whether to buy genuine or third-party modules. A respondent reported that on a new X620 a third-party SFP+ linked but its DDMI data could not be read, and that Extreme provides no help for problems involving…
With auto-negotiation on, CRS317 and CRS326 SFP+ interfaces ran at 10G; with auto-negotiation=no, speed=10Gbps and full-duplex=yes the log still reported link up (speed 1G, full duplex) regardless of the advertise settings. On a CCR1009 the same configuration produced no-link instead, showing that…
A Mellanox ConnectX-4 Lx (MCX4121A-ACAAx, firmware 14.32.1900) in a Ryzen desktop (Fedora 41 and Windows 10) detected the interface but reported Cable is unplugged with two FS.com SFP28-25GLR-31 modules and a 40 m single-mode LC duplex patch; a MikroTik router recognised the same optics. The poster…
With an Aruba 2930F connected to a server through a Stornet-branded J9283D-SN passive 3 m SFP+ DAC, port 50 dropped the link immediately after it came up and port 52 flapped with the log message FFI : Port: 52 Excessive link state transitions. The same cable worked on ports 49 and 51, and fibre…
Dell R740xd servers with OEM Intel X710 adapters were cabled to Cisco switches with SFP-H10GB-CU5M and SFP-H10GB-CU3M DACs. Two cables linked, five did not; the working ones carried a blank or V02 version ID (made 2013), the failing ones V03 (made 2019), all identified as SFP-10GBase-CX1 on the…
Cisco-compatible CWDM SFP modules that had worked in Dell PowerConnect 6024 and 6224 switches produced a transmit failure error in a PowerConnect 8024F, presumably because the 8024F ports are SFP+. The poster considered Finisar FWLF1524P2Vxx modules but wanted confirmation from someone with a…
After a complete power loss a Dell R740 with a four-port Broadcom NDC (2x SFP+, 2x 1GbE) booted normally but the fibre SFP+ modules stayed unpowered and disconnected; a reboot did not help and only physically removing and reinserting the modules restored them. Dell support pointed at drivers and…
Between VxRail Dell S5212F-ON TOR switches and Cisco C9500-48Y4C switches, FS.com SFP28 DACs behaved inconsistently: a 5 m cable custom-coded Cisco on one end and Dell on the other came Line Up, Protocol down; a 2 m Cisco/Cisco-coded cable linked; a 3 m cable would not link even with the 2 m…
A QSFP28 100 Gb DAC supplied by Supermicro linked two Dell S5248F-ON (OS10 10.4.3.6) switches fine, but between the Dell and a Supermicro XEM-100 the port showed up, line protocol is down. Multiple FEC and negotiation combinations were tried. The thread received no answers. Hardware involved: Dell…
With a CSS326-24G-2S+ (SwOS 2.6) and a server with an Intel 82599 card, two different S+DA0001 DACs and two Intel cards never linked; two CSS326 switches connected by DAC only achieved 1 Gbps. A later reader on SwOS 2.12 with an 82599 reported the same. No solution was posted. Hardware involved…
