Latest questions from the community.
A Raspberry Pi tool for SFP/SFP+ EEPROM: -r prints connector, transceiver spec, wavelength, vendor, part, serial, date and checksums; -d dumps the whole EEPROM; -c recaculates checksums and offers to write the correct value; -m reads DOM sensors (temperature, voltage, bias, power). A vendor variant…
An open-source hardware and software project to read and modify SFP/SFP+ EEPROM, aimed at changing the OUI and other identity fields so a module works with third-party transceivers where the vendor has not fully disabled write access. It uses a Cypress CY8CKIT-059 board as the USB interface. As of…
A tutorial on recoding SFP/SFP+ EEPROM so a module works with a different vendor's switch. It uses a Cisco Twingig housing to reach the SFP I2C pins and wires four lines from the Pi GPIO (3.3 V, GND, SDA on GPIO3, SCL on GPIO5). It shows detecting 0x50 (and optional 0x51 DOM) with i2cdetect, points…
Discussion of why re-coded modules fail Cisco validation: Cisco SFPs carry a unique signature tied to each serial number in bytes 96-127, and editing vendor name or serial makes the signature no longer match, so the switch rejects the module unless the signature is regenerated. Hardware involved…
A small toolset that reads and writes SFP EEPROM over I2C with a CH341A programmer plus an I2C sniffer. The author found that sigrok/PulseView did not work with the analyser, that a v1.0.5 SFP coder firmware reported success while silently not writing the module (proven by I2C traces), and that the…
A reference post on the memory layout used when programming transceivers: SFP blocks A0h (serial ID/vendor, often write-protected) and A2h (diagnostics, page-select byte 7Fh, page 00h/01h user-writable); QSFP block A0h with page-select 7Fh, page 00h identity write-protected and page 03h user…
Reverse-engineering notes on the SFP Wizard: it reads a module's part number (page A0h bytes 40-55), looks it up in an embedded password database and sends the matching unlock password, falling back to brute force when unmatched. It traces the firmware evolution: v1.0.5 tried only the first…
A notes repository on hacking SFP/QSFP EEPROM: SFPs present EEPROM at I2C 0x50 and DOM plus vendor/password features at 0x51; locked moddules need a 4-byte password written to 0x51 bytes 0x7b-0x7e. It lists several known unlock passwords and evaluates write methods (off-the-shelf coder limited to…
The poster programmed an OEM copper SFP with a 256-byte firmware dump; the switch recognised the type but the module received no data, whereas the original worked, and no password error appeared. It failed on several units. Hardware involved: OEM copper SFP (24C02 EEPROM). Reported…
Users needed to write to password-protected SFP/QSFP/XFP modules from HP, Cisco, Finisar and JDSU. The thread documents the two protection levels: a host/user password protecting the user-writable area (A2h offset 7Bh on SFP, A0h offset 7Bh on QSFP/XFP) and a manufacturer password protecting the…
After a power outage an Aruba Instant On 1930 (24 ports plus 4 SFP) still recognised inserted SFP modules but every SFP port stayed down; inserting a new transceiver made the port LED blink once and then nothing. The poster asked for diagnostics or replacement options. Hardware involved: Aruba…
A Meraki MX95's WAN2 SFP would not link to an upstream Extreme switch, while the same SFP and patch linked to a Netgear switch, which in turn linked to the Extreme. The same happened with an MX85 against an AT&T-provided Ciena device. Cisco-certified and Extreme-certified SFPs were tried in all…
A pre-built HL15 server (Supermicro X11SPH-nCTPF wth Intel X722 SFP+ ports, Rocky Linux) would not link to a UniFi USW-24-POE over a VANDESAIL SFP+ DAC: the switch port stayed Disconnected under every negotiation setting on both sides. After ordering a 10Gtek cable the host reported network driver…
The poster could read and write OEM SFP variants with a REVELPROG and SFP adapter but not three Finisar references, suspecting manufacturer password protection. Finisar only documents the MSA user-EEPROM password in datasheets, not the proprietary manufacturer password, and the same happened with…
After upgrading OPNsense from the 21.x series to 22.7 a 10G SFP+ port stopped working with interface is disabled due to unsupported sfp; the newer Intel driver actively disables unrecognised modules. The poster tried to set ixgbe.allowunsupportedsfp=1 as a system tunable, which was not accepted…
A used IBM Emulex dual-port 10GbE SFP+ PCIe card (bent bracket, loose heatsink) made both TrueNAS Core and a Windows 10 PC hang for a long time during boot; the switch showed a link but neither OS saw the interface as active. Hardware involved: IBM Emulex dual-port 10GbE SFP+, Chelsio NICs, Intel…
On an Alta Labs Route 10 the SFP+ ports recognised FS.com SFP-H10GB-CU2M and 10Gtek CAB-10GSFP-P2M DACs (which had worked on MikroTik CRS devices) but no link came up against a MikroTik CRS309-1G-8S+; forcing 1G baseT full gave a 1 Gbps link only. Staff requested diagnostics and ethtool -I output…
A Chelsio CC2-S320E-SR (110-1114-30) dual-port SFP+ card recognised by TrueNAS would not link to a Dell PowerConnect 6224 through a QSFPTEK 0.5 m passive DAC: no link lights and status: no carrier, even after assigning IPs to cxgb0/cxgb1. Looping the DAC between two switch ports worked, and looping…
On an inexpensive firewall appliance (Intel Atom C3758R, six 1GbE igc ports and two SFP+ cages wired to the CPU) OPNsense showed four ix interfaces instead of two and the SFP+ ports stayed red/down with a copper SFP+ RJ45 module, although the link LEDs lit. ifconfig -v identified ix0/ix1 as the…
On a Lanner NCA-1510 the four Intel X553 ports (ix0-ix3) worked, but two Intel I210 Gigabit Fiber Network Connection interfaces (device 0x15368086) with SFP cages were absent in OPNsense even after loading ifigb via tunables; pfSense detected them by default. Another user had the same with a…
Replacing an old Dell switch with an Extreme 5420M-24, the same SFP module that had worked in the Dell would not bring the network up: the uplink port was active with rising TX counters but RX stayed at zero, no DHCP address, no ping to the firewall, and a new SFP+ module behaved the same. Ethernet…
A TP-Link T1700G-28TQ (V3, firmware 3.0.0) with a TL-SM311LM module was linked to a Netgear ProSafe GS716T with a SkyLane SFP85P55GE0B989 module. The TP-Link port showed 1000M with a flashing LED while the Netgear port stayed down, and throughput was about 1 Mbps; with a media converter the link…
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…
A FortiGate 500E displayed the message This port is using a third-party transceiver on an SFP+ port; the poster asked whta it meant and which SFP+ specification to use. There were no errors or link problems, only the log line, so the real question was whether it signals a fault, degrades support…
On an Extreme Summit X670 two QSFP+ ports were configured as 4x10G, the ports were set to 10000 full duplex with auto off and VLANs assigned, but a breakout cable with an MPO connector to six LC connectors produced no link on the QSFP+ sie or on the SFP+ side. Hardware involved: Extreme Summit…
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…
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…
On Zyxel XGS4600 switches, 10G and 1G SFP+ transceivers (including an FS.com DWDM-SFP10G-80) intermittently stopped transmitting; only removing and reinserting the module restored the link. Transceiver statistics at that moment showed TX power -inf dBm, voltage at the 3.00 V low alarm and TX bias…
A T2600G-28TS (TL-SG3424) uplinked over fibre to another building using D-Link transceivers and media converters showed the SFP port UP and transmitting but never receiving packets. Restart, factory reset and other SFP ports were tried. Another user returned the switch after failing to link it to…
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…
