Latest questions from the community.
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…