Latest questions from the community.
Trying to replace the ISP terminal in my home rack with a GPON stick straight in the router, so the fibre lands in one box instead of two. The stick is recognised, and that is where the good news ends. Turris Omnia on Turris OS 5.0.3, stock kernel Huawei MA5671A GPON stick with unlocked firmware…
We have a dark fibre span of roughly 80 km where the owner will lease us exactly one strand - a second core is either not there or priced like a small building. Both ends terminate on chassis with XFP cages, and the service on top of it has to be 10 GbE. So what I need is a single-fibre BiDi XFP…
I keep a shelf of pulled SFPs at home and I would like to be able to read their EEPROM, repair a module whose checksum got mangled, and occasionally recode one for a switch that is picky about vendor strings. Buying a commercial programmer for a handful of modules a year makes no sense here, so I…
An Aruba/HPE 2530-48G-2SFP+ on firmware 16.01.0012 logged Port contains a transceiver not made by Hewlett Packard Enterprise with the advice to use onlly genuine transceivers, and refused the modules; ironically one of the rejected transceivers was HP-branded. The poster asked whether a command…
We are refreshing a pair of aggregation closets and the optics line is the part management keeps poking at. The switches are EXOS boxes and the plan was to fill the 40G uplinks with generic QSFP+ DACs, the same way we already do on the access ports. Then someone on the team dug up a note about a…
Four HP ProCurve 6120XG blade switches (516733-B21) refused J9150A 10G SR SFP+ transceivers that the datasheet lists as supported; show tech transceivers reported them as unsupported. The switches ran Z.14.56. The poster asked whether a firmware upgrade or a configuration setting was needed…
I finally moved my VDSL2 line off the ISP box and terminated it on the Turris Omnia itself, mostly so that PPPoE runs on the router instead of on a second device in bridge mode. The setup part was pleasant: seat the stick in the cage and the WAN interface simply moves onto the module, leaving the…
The poster wanted to connetc Aruba 2540 switches (JL357A, firmware YC.16.09.0001) to Cisco Catalyst 9300 switches using Cisco SFP-H10GB-CU3M DACs. After enabling allow-unsupported-transceiver the cables were still not recognised: show tech transceivers listed the port as unsupported, the LED…
I inherited a Sun Network 10GbE Switch 72p with a couple of legacy boxes hanging off it that will never do more than a gigabit. The plan was to drop a 1G capable module into one of the SFP+ cages and be done with it. Sun Network 10GbE Switch 72p, SEFOS CLI over the serial console x2129a dual-rate…
H3C-SFP-10G-T-SO 10GBASE-T copper modules (from FS or Solid Optics) worked out of the box in a FlexFabric 5940 (JH398A) with the JH181A 24-port SFP+ card, but in a FlexFabric 5945 (JQ076A) with the same card the ports only came up after manually running port up-mode on the interface. The poster…
We are standing up four DGX Spark nodes for disttributed training and hung them off a MikroTik CRS812-8DS-2DQ-2DDQ. The plan was one 400G QSFP-DD port on the switch feeding two nodes at 200G each, so a couple of breakout cables cover the whole cluster. MikroTik CRS812-8DS-2DQ-2DDQ, QSFP-DD ports…
Two Flex System enclosures, each with an EN4093R 10Gb Scalable Switch (option 49Y4270) as the network module. Ports come back error-disabled after a chassis power event, and less often drop into the same state while everything is running. It is not always the same ports, which is what makes this so…
Home rack, and the RB5009 has exactly one SFP+ cage. I wanted a second copper gigabit uplink out of it rather than pulling fibre across the room, so a copper module went in instead. MikroTik RB5009UG+S+IN, RouterOS 7.1rc4 MikroTik S-RJ01 1000BASE-T copper SFP in sfp-sfpplus1 Cat6 patch, about three…
The poster operated old HP/H3C A5800 switches (JC100A, JC103A) with many SFP modules of mixed coding. Modules with H3C in A0h bytes 60h-62h worked but logged This is not a supported transceiver for this platform, and DDM plus serial/date information were unavailable. Copying the full data from a…
Even with allow-unsupportted-transceiver enabled, HPE Aruba 3810M and 2930M switches showed an amber fault for generic SFP+ modules, including ones recoded to masquerade as a J9151A. The author traced the behaviour to HPE's HPIDv2 challenge-response authentication: the module EEPROM carries a flag…
Rebuilding aggregation at one of our sites: a CRS326-24S+2Q+RM takes the custmer SFP+ ports and uplinks over 40G into a Huawei S6720. Short run inside the same rack, so a passive DAC rather than optics. MikroTik CRS326-24S+2Q+RM, QSFP+ port qsfpplus1-1 Huawei S6720-54C-EI-48S-AC, plain 40GE port…
Small home lab. I flashed a Linksys LGS328C over to OpenWrt SNAPSHOT to get away from the stock web interface. Everything survived the move except one SFP28 port that used to work perfectly well. switch: Linksys LGS328C (Realtek rtl930x), OpenWrt SNAPSHOT module: Dell S28-10G-25G-SR-85C, dual-rate…
I look after a small office network, one switch closet, and the four SFP+ cages on our access switch carry the 10G links to the server rack. It ran for months without a thought and now one cage is simply gone. TP-Link TL-SG3428X-M2 (V1), firmware 1.20.4 Build 20241104 Rel.40746, adopted in Omada…
We have a leased dark pair between two POPs, roughly 115 km, and both ends land on a Cisco Catalyst 6506. The requirement is modest: one gigabit, no DWDM, no channel plan, just a working point to point link. What came back when I asked Cisco how to build it from their own catalogue was an…
Moving a pair of hypervisors onto Fibre Channel storage, and one host refuses to present a single LUN while the very same hardware works when the card is handed to a VM. QLogic QLE2692, ISP2722-based 16/32Gb FC, both ports cabled Fujitsu Eternus DX100 S5 at the other end Proxmox VE 6.2 host…
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…
