Latest questions from the community.
An operator asked how to use non-Intel SFP+ modules for 10G fibre on Intel adapters under Linux. The replies summarised the practical rules: for 82599/X520 class NICs the ixgbe module parameter allowunsupportedsfp must be set, and on dual-port cards it must be given per port…
On Aruba 2930F switches (JL255A) the poster installed new J9151E 10G SFP+ transceivers (part 1990-4727) that the transceiver guide lists as supported, but every unit was reported as Unsupported Transceiver (SelfTest Err#128000) and show tech transceivers showed ?? for type and serial. J9281D DACs…
Two service providers shared a fibre with CWDM multiplexers. The existing 1310 nm channel worked, but after adding a 1471 nm channel the transmitting side saw frames leave (confirmed with packet captures) while the far end received nothing, even though light levels looked normal. The provider had…
With an Aruba 2930F connected to a server through a Stornet-branded J9283D-SN passive 3 m SFP+ DAC, port 50 dropped the link immediately after it came up and port 52 flapped with the log message FFI : Port: 52 Excessive link state transitions. The same cable worked on ports 49 and 51, and fibre…
The poster bought eight J9150D 10G SR SFP+ transceivers for an Aruba 5406R zl2 chassis with a J9993A module. Every module lit the orange LED and logged Unsupported Transceiver. (SelftTest Err#098000), even though the compatibility documents list this combination and the chassis had already been…
An operator asked about the practical behaviour of Brocade equipment with third-party SFP/SFP+ optics. Experience shared on NANOG: Foundry-heritage platforms (FastIron, NetIron, ICX including ICX7750) generally bring up any MSA-coded module, but the optical-monitor (DDM) function may be unavailable…
On a Juniper EX4600 running Junos 14.1X53-D27.3 the poster inserted a non-certified 1G single-mode WDM (BiDi) SFP, 20 km, TX 1550 / RX 1310 nm with DDM, into ge-0/0/1. The interface never appeared: show interfaces returned error: device ge-0/0/1 not found, and the log recorded XCVR: Unit 1, Fibre…
A network operator received QFX3500 switches that would not bring up third-party SFP+ transceivers even though a Juniper sales engineer had said they would work. JTAC stated that non-Juniper SFP+ optics would never be supported on the platform. The switch detected the presence of the module but…
On an Arista 7050QX running EOS 4.14 the poster tried to use third-party QSFP+ DAC cables; the ports went to errdisable as unqualified transceivers. They patched the XcvrAgent.py agent under /usr/lib/python2.7/site-packages to skip the manufacturer check, which cleared the errdisable state but left…
In a NANOG discussion about vendor lock-in, an operator described two concrete failures. First, a third-party optic answered I2C reads too slowly; the switch vendor's polling code did not handle the timeout and crashed the linecard control plane, and the vendor refused to treat it as a bug because…
While staging an EX2300-48P and an EX2300-24P (both Junos 18.2R3-S5.3) with non-Juniper SFP+/SFP modules, the 48-port switch recognised the transceivers and created interfaces, but the 24-port switch showed nothing in any of its four uplink ports; show chassis hardware listed PIC 1 as 4x10G…
Juniper-branded SFP modules were intermittently reported as unsupported or not supported in the chassis hardware output right after an EX or MX device booted. Rebooting the device or reseating the SFP made the module recognised again, which was frustrating in production. The poster wanted to know…
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 poster had an existing multimode fibre run of about 200 m that could not be replaced and only single-mode 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…
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…