Latest questions from the community.
We took over a small aggregation site and one of the 10G uplinks has not come up since the module in it was swapped. The module is listed as incompatible with the CRS226, so that is where suspicion landed first, but the readings do not look like a rejected module to me. MikroTik CRS226 at the…
The poster tried to link an HPE FlexFabric 5900AF and a Dell S5212F-ON at 10 Gbps with DAC cables that had been custom-made with an HPE-coded end and a Dell-coded end. Both ports were forced to 10G full duplex, but no link came up. On the HPE side the interface reported Media type is stack wire…
We are consolidating a pair of R630s onto 10G and the cabling to the top of the rack is copper, so instead of pulling fibre I put 10GBASE-T SFP+ modules into the X520 cards. The switch end takes them without a word. The servers refuse to. Dell PowerEdge R630, Intel X520 (82599), dual port FS…
A customer saw errors on a fibre link and suspected a speed mismatch with a 1G far end. The poster asked whether 10G SFP+ transceivers are backward compatible with 1G, or whether the modules had to be swapped for 1G SFPs to talk to the gigabit device on the other side. Hardware involved: Aruba…
I run a provider's network with a mixed fleet of modules, so I regularly have to prep modules for specific switches. I want to finally understand the mechanics of the check instead of guessing at dumps. What I'm working with: Cisco Catalyst 2960X-24PS-L, the pickiest one in the fleet QTECH…
Two Aruba 2930F switches (JL256A, firmware 16.05.0003) were to be stacked with VSF over an HPE DAC. With allow-unsupported-transceiver enabled the DAC passed traffic on normal ports, but as soon as the ports were made VSF member links the stack would not form. Replacing the DAC with supported 10G…
Home setup. The fibre handoff from my provider is a 1G BiDi module and I would like it in the firewall itself instead of kepeing a switch in front of the box just to convert media. Protectli Vault 6 running pfSense, X710 ports, ixl driver the provider-supplied 1G BiDi module, an EZConn…
Servicing a small office network, two buildings linked by a single single-mode fiber that contractors pulled. The job was supposed to take half an hour: bring up a gigabit link between the switches in the two buildings. It's been two weeks and it still won't come up. What's installed: main…
We inherited a pair of Connectrix DS-7720B (Brocade G720) for a new fabric, and I haven't got anywhere near zoning yet, because not one of the double density ports will come up. Every single one of them says the same thing in switchshow: What is in the rack: Connectrix DS-7720B / Brocade G720…
An HPE 2920 (J9729A, firmware WB.15.17.0009) with the J9731A 10G expansion module was connected to a DL380 Gen8 with a 560SFP+ NIC using a genuine HPE X242 3 m SFP+ DAC (J9283B). Port A1 with a J9150A SR module worked, but port A2 with the DAC logged Transceiver type not supported in this port and…
The poster needed to connect stacked Aruba 6300F (JL665A) switches to a 6300M core (JL658A) at 10 Gbps over more than 3 m. J9283D 3 m DACs worked for short runs and the older 3810/2930 platforms supported a 7 m J9285D cable, but that cable is not listed for the 6300. The question was whether the 5…
I keep a small pool of shared modules: the nodes are scattered around the city, and I have to recode SFP modules for almost every switch that isn't mine. With gigabit modules the routine has been solid for a long time, but a 10G one just stopped me cold. What's on the bench: a programmer with an…
Bought a StarTech ST10GSPEXNB to give a backup server a 10G SFP+ port, on the assumption that a card sold with a Linux driver would build against a current distribution. That was optimistic of me. StarTech ST10GSPEXNB, Tehuti TN4010 chip Debian 11, kernel 5.10.0-13-amd64, matching headers installed…
I am replacing the operator ONT with an SFP GPON stick on the Linux box that terminates our WAN, and the stick behaves nothing like a transceiver. Push it in and the cage stays silent for half a minute or more, long enough that I twice assumed the module was dead, and when the kernel finaally does…
We look after the switch management firmware on our own hardware, and ever since the SP/FPGA interface was changed from memory mapped buffers to a FIFO, the transceiver inventory has been coming back as junk on some ports. QSFP28 optics, all of them AFBR-89BDDZ out of the same batch reads go over…
We are bringing up a leaf on an Accton AS9716-32D running SONiC master (build master.207726). Four of the 400G-capable ports have to run at 100G towards a firewall pair, and not one of them will link. Accton AS9716-32D, SONiC master.207726 INNOLIGHT TR-FC13R-N00 QSFP28 LR4 in the switch cage…
I am writing a small poller that pulls temperature, voltage, bias and optical power straight off the modules on our whitebox boxes, so we get a trend line instead of someone eyeballing a link after it has already started erroring. The NOS prints pretty values, but I want the raw numbers with the…
The poster had an Integra Optics tunable DWDM SFP+ (1528.77-1566.72 nm, 96 channels, 80 km, 10G, sold as Calix/Arista compatible) in an Arista switch. Changing the frequency and configuring the ITU channel through the Arista CLI had no effect: the module kept reporting the same wavelength. The…
An operator asked how to use non-Intel SFP+ modules for 10G fibrre 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-certifiied 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 thhird-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 moules, 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 SFP/SFP+…
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…
