EEPROM read/write, coding, passwords, checksums, SFF-8472 / SFF-8636 / CMIS fields
A Python library to create, read and modify the 256-byte A0h page of SFP EEPROM per SFF-8472. It exposes named fields (vendor, part, serial, wavelength, bit rate, encoding, link lengths, diagnostics options), generates images from scratch or from a binary, and validates/recalculates checkssums. It…
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…
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…
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…
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…
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…
A good half of my work is putting one company's optics into another company's switch, so I spend a lot of time asking a module what it thinks it is. My toolbox for that is currently one command deep, and I would like to know what else is worth putting on the bench machine. Linux boxes with SFP+ and…
Bench work: re-coding a small batch of SFP+ modules so they carry the vendor string and part number the customer's kit expects. The edit itself is trivial in a hex editor, the write goes through, the read back matches byte for byte what I wrote - and the host still throws the module out. generic…
Installing a new MES2324FB at a site to replace old hardware. The uplink is 1G fiber to an Alcatel 6224, Foxgate modules from the same batch as at neighboring sites. Setup: Eltex MES2324FB, firmware 4.0.4.7, also tried 4.0.6 - no difference 1G SFP Foxgate on both ends of the link far end - Alcatel…
We are a small regional ISP rebuilding the optics budget for next year. Every 10G spare on our shelf is coded for exactly one platform, so the spares pool is roughly three times larger than our failure rate justifies. The idea on the table is to buy re-codable modules and code them ourselves as…
I run a backup storage system in a data center. A pair of DD9900 in HA, network ports on the NDC QLogic. After a reboot or reseating the module, port ethMa stops seeing the transceiver, and it's not a one-off - it's a stable, repeating pattern. Dell DD9900, DD OS 7.2.0.95, HA configuration NDC…
We run a pair of ThinkSystem NE1032 RackSwitch units as top of rack in a small colo cage. The Lenovo-branded optics we inherited only cover half the ports, so the rest got filled with generic SFP+ modules and a couple of short DACs out of the same batch we already use on other vendors' switches…
We are adding capacity to a small FC fabric and bought compatible 16G short-wave SFP+ from an optics supplier instead of paying the switch vendor price. The switch refuses them. Brocade G610, Fabric OS 9.x generic-coded 16G SWL SFP+, correct wavelength and reach according to the label Brocade-coded…
The thread starter documented that 82599-based X520 cards carry an undocumented EEPROM bit (IXGBEDEVICECAPSALLOWANYSFP, lowest bit of the capability word at byte offset 0x58, typically 0xFC locked / 0xFD unlocked) that decides whether non-Intel active SFP+ modules are accepted on ESXi and Windows…
