Latest questions from the community.
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 poster 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 adapters. 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 throughout…
The poster's Cisco Catalyst C9500-48Y4C switches (IOS XE 16.12.04 after an upgrade) refuse to work with a batch of genuine Cisco SFP-10G-SR modules (VID V03, serials AVD2231D3TE and AVD2231D3RW): 'show inventory' lists them as 'GE ZX' instead of 'SFP+ 10GBASE-SR' and the ports stay non-functional…
The poster's Intel Ethernet Converged Network Adapter X710 would not come up with third-party Fiberxon 10G SFP+ modules: the i40e driver, version 1.2.48, refused to initialise and reported "The driver failed to load because unsupported module type was detected." They asked how to switch on an…
The poster, validating their product against Cisco Nexus 9000 switches (a Nexus C9332D-GX2B chassis), is blocked by bug CSCwo18785: configuring 200G on a QSFP-200G DAC fails with 'ERROR: The transceiver doesn't support this speed'. The cable is a Mellanox MCP1650-H002E26 200GbE DAC; connected…
The poster compiled and loaded i40e 3.4.2 on Ubuntu 16.04 for an Intel XL710-QDA2 dual-port 40GbE adapter. The driver loaded fine, but as soon as non-Intel QSFP+ cables were attached dmesg reported "Rx/Tx is disabled on this device because an unsupported SFP+ module type was detected." and no link…
The poster wanted to use a Finisar FCLF8521P2BTL 1000BASE-T copper SFP in an Intel X710-DA2 running NVM 7.1. Intel's X710/XXV710/XL710 Feature Support Matrix (rev. 3.4, Nov 2019, doc 332191-024) lists single-speed SFP 1GBASE-T transceivers with support limited to Finisar FCLF-8521-3, Kinnex A…
While rolling out single-mode fiber between Cisco CBS350-8MGP-2X switches (firmware 3.4.0.17) with SFP-10G-LR modules, the poster hit strange behaviour: the link only comes up if the duplex LC connector is split and the TX fiber is inserted first, then the RX fiber. Inserting the joined LC…
The poster connects a Cisco Catalyst C9300X-24Y to a FortiGate firewall with a 25G SFP-H25G-CU2M DAC. Whenever the DAC is inserted the switch logs '%PLATFORMPM-6-MODULEINSERTED: SFP module inserted with interface name Twe1/0/23' followed by '%PLATFORMPM-6-DIFFERENTMODULEINSERTED: Warning: SFP…
A Cisco Nexus 5672UP fitted with a 10GBASE-SR SFP+ could not connect to another switch that uses a 1000BASE-SX (1 Gbps) transceiver; both ends are multimode optics. When the poster changed the port speed, 'show interface brief' displayed an 'SFP checksum error', and swapping the Nexus optic for a 1…
The poster is searching for GPON or XGS-PON SFP ONT sticks with a built-in MAC that work in Cisco routers, since Cisco does not sell such modules. Previous attempts with third-party ONT sticks were largely unsuccessful even after enabling 'service unsupported-transceiver'. In a follow-up the poster…
Before replacing an old switch with a Cisco Catalyst 9300-M, the poster wanted to know whether the existing SFP could be reused and posted the 'show idprom interface gigabitEthernet 1/1/1' output: Vendor Name CISCO-FINISAR, Vendor Part Number FTLF1318P2BCL-C3, serial FNS15510U5B, 1310 nm, single…
On an IOS XR router (RSP-based ASR 9000 class, observed on IOS XR 4.x and 5.x), the poster configured a tunable DWDM XFP with 'controller dwdm 0/1/0/0', 'admin-state maintenance', 'wavelength 55', 'admin-state in-service' and then brought the TenGigE interface up. The running configuration shows…
The poster's newly acquired Cisco Catalyst 9300 (with an 8-port 10G SFP+ network module) would not link to a Cisco Catalyst 4503-E that only has 1G SFP ports. Suspecting a 10G-versus-1G speed mismatch, the poster tried to force the 9300's 10G SFP to operate at 1G with the 'speed' command, but the…
Two Cisco Nexus 93108TC-FX3P switches on NX-OS 9.3(11) are connected with genuine QSFP-100G-CU1M DACs but the link never comes up. The compatibility matrix says the cable is supported from NX-OS 9.3.5. The port config is a plain 'switchport mode trunk' / 'no shutdown', and 'show interface eth1/54…
The poster uses Ubiquiti (UBNT) SFP and SFP+ modules, both multimode and single-mode, in Cisco switches. They work perfectly in Catalyst 9300 and 3650 switches with current IOS, but in a Catalyst C1000 and a Catalyst 2960 the modules are detected on insertion yet reported as 'unknown' in 'show…
The poster asked whether anyone had used third-party optics in a Cisco Catalyst 9300 series switch running IOS XE Everest (16.x), and specifically whether the hidden global command 'service unsupported-transceiver', long used on older Catalyst platforms to accept non-Cisco SFPs, still functions on…
The poster needs a 100GE link between a Cisco NCS55A2-MOD (NC55-MPA-4H-S MPA) and a Cisco Catalyst C9500-48Y4C using a QSFP-100G-CU1M DAC. Both platforms list the cable as supported, yet the link never comes up at the physical level. Because the Catalyst 9500 lacks 100G auto-negotiation (bug…
The poster was connecting a Cisco Nexus 93180YC-FX to an Arista 7050SX3 with a 25G AOC sold as Cisco/Arista compatible. The Nexus detects the transceiver, but 'show interface status' reports the port as not connected. A 10G AOC from the same vendor works fine between the two switches, and the same…
The poster wanted to run a link bidirectionally over one strand of single-mode fiber on a Cisco Small Business 300 series switch. Cisco's SMB catalogue lists the MFEBX1 100 Mb BiDi SFP (transmitting at 1310 nm and receiving at 1550 nm), but the poster could not find a Cisco part number for the…