Latest questions from the community.
The poster needed to connect a MikroTik CRS328-4C-20S-4S+RM to an HP 1820-24G-PoE+ over 200-500 m of outdoor aerial fibre and asked which SFP modules to buy and how to verify compatibility before purchase. The HP compatibility table listed only J4859C as a single-mode SFP, while MikroTik offered…
The postter had an existing multimode fibre run of about 200 m that could not be replaced and only single-moode SFP modules available. The question was whether a 1G single-mode SFP pair would establish a stable link over multimode fibre, and what the practical limits were. The thread also raised…
The poster wanted to verify whether an HPE StorageWorks 81B 8 Gb Fibre Channel HBA (AP769-60001) fitted with an AJ716B SFP could be used in an HPE ProLiant DL380 Gen10 server (P02464-B21) and asked for a tool where part numbers can be entered to get a compatibility verdict. No error had occurred…
The poster wanted a cheap 10G link between servers with Intel X520-DA2 NICs and an HP switch and worried that a direct-attach cable is coded either for Intel or for HP but not both. A respondent shared that two X520-DA2 cards would not link directly over a DAC in their case, but a Dell DAC…
The poster wanted to run 100 Mbps fibre SFP modules in a D-Link DES-3200-28F but the vendor compatibility list only named older switches (DES-1228, DES-1252, DGS-3612G). The question was whether the list was simply stale or whether the modules would be rejected by the newer switch. A related…
The poster owned a MikroTik RB962UiGS-5HacT2HnT (hAP ac) with a single SFP cage and had two spare 850 nm modules on hand: a Cisco-branded AFBR-57F5PZ-CS1 and an Intel-branded FTLX8571D3BCVIT1. The ISP delivered the service over a single fibre strand rather than a duplex pair, and the posster wanted…
The thread starter had a set of Cisco EEPROM images (SX, LH, ZX types) but no CWDM images and wanted CWDM SFP modules to show up on Cisco switches as CWDM/WDM optics rather than being misidentified as SX or LX. Without a correct image the switch either reported the module as unsupported or forced…
The thread starter wanted to reprogram GBIC and SFP module EEPROMs but found that guides were disappearing from forums. Questions covered which programmer to use, where to attach the I2C lines on the module, whether the module needs 5 V (GBIC) or 3.3 V (SFP), and how to treat the memory as a…
The poster planned a server with an Intel X710-DA2 dual-port SFP+ NIC connected to two Ubiquiti EdgeSwitch 48 Lite units, with LACP between the switches. Six 10G SFP+ modules were needed (two for the server side, four for the switches) and the question was which modules would be recognised by both…
The poster wanted to dump the EEPROM of a QSFP+ transceiver plugged into an Intel XL710-QDA1 and ideally read live DDM values such as received optical power, as they were used to doing with SFP modules on other adatpers. With i40e 2.0.23 and firmware 5.05 0x800028a2 1.1568.0, ethtool -m eth0…
A brand-new retail Intel E810-XXVDA2 on Windows Server 2022 (Intel driver 1.12.164.0 from release package 28) was connected to an SFP28 port of a Ubiquiti USW-Pro-Aggregation switch. With an SFP28 DAC the link came up at 25G immediately, but with SFP28 optical transceivers (Ubiquiti…
On Ubuntu 18.04 (kernel 5.4.0, ethtool 5.3, i40e 2.8.20-k) the poster used 25G XXV710-based NICs bought from FS.com (FS part XXV710AM2-F2, Intel XXV710 chipset). Link and error-free wire-speed traffic worked, but reading a transceiver's DMI data with sudo ethtool -m enp4s0f0 failed with "Cannot get…
The poster was building a server that needed a 1 Gbps single-mode fibre uplink and wanted a PCIe card with two to four SFP cages so any optic could be used later. The core doubt: switches usually accept plain 1G SFP optics in SFP+ ports, but is the same true for 10GbE server NICs, or would the NIC…
For a deployment on Dell PowerEdge R630 and C4140 servers the poster had Intel X520-SR2 adapters (E10G42BFSR) fitted with the bundled Intel FTLX8571D3BCV-I3 10GBASE-SR SFP+ modules (850 nm, 300 m multimode). The uplink switch is a Huawei Quidway 9300 whose SFP+ ports carry 10GBASE-LR (1310 nm)…
The poster spent a day and a half chasing an Intel 82599EB-based 10G SFP+ NIC that VMware ESXi 6 reported as down although the link LEDs were green on both ends of the fibre and the Cisco 8500 switch showed the port up/up. The cause turned out to be the Cisco SFP-10G-LRM module used throuhout their…
