Latest questions from the community.
Replacing an old Dell switch with an Extreme 5420M-24, the same SFP module that had worked in the Dell would not bring the network up: the uplink port was active with rising TX counters but RX stayed at zero, no DHCP address, no ping to the firewall, and a new SFP+ module behaved the same. Ethernet…
A TP-Link T1700G-28TQ (V3, firmware 3.0.0) with a TL-SM311LM module was linked to a Netgear ProSafe GS716T with a SkyLane SFP85P55GE0B989 module. The TP-Link port showed 1000M with a flashing LED while the Netgear port stayed down, and throughput was about 1 Mbps; with a media converter the link…
The poster had free thrid-party SFP/SFP+ samples that worked on Extreme switches and asked whether to buy genuine or third-party modules. A respondent reported that on a new X620 a third-party SFP+ linked but its DDMI data could not be read, and that Extreme provides no help for problems involving…
A FortiGate 500E displayed the message This port is using a third-party transceiver on an SFP+ port; the poster asked whta it meant and which SFP+ specification to use. There were no errors or link problems, only the log line, so the real question was whether it signals a fault, degrades support…
On an Extreme Summit X670 two QSFP+ ports were configured as 4x10G, the ports were set to 10000 full duplex with auto off and VLANs assigned, but a breakout cable with an MPO connector to six LC connectors produced no link on the QSFP+ sie or on the SFP+ side. Hardware involved: Extreme Summit…
Monitoring reported packet loss toward an ESXi iSCSI host; on the Dell S4810 (FTOS 9.11(2.6)) the interface TenGigabitEthernet 0/37 showed the warning Non-qualified pluggable media present, SFP+ type is 10GBASE-CU2M because a non-Dell DAC was used. The link was up with normal traffic (about 16…
Dell R740xd servers with OEM Intel X710 adapters were cabled to Cisco switches with SFP-H10GB-CU5M and SFP-H10GB-CU3M DACs. Two cables linked, five did not; the working ones carried a blank or V02 version ID (made 2013), the failing ones V03 (made 2019), all identified as SFP-10GBase-CX1 on the…
On Zyxel XGS4600 switches, 10G and 1G SFP+ transceivers (including an FS.com DWDM-SFP10G-80) intermittently stopped transmitting; only removing and reinserting the module restored the link. Transceiver statistics at that moment showed TX power -inf dBm, voltage at the 3.00 V low alarm and TX bias…
A T2600G-28TS (TL-SG3424) uplinked over fibre to another building using D-Link transceivers and media converters showed the SFP port UP and transmitting but never receiving packets. Restart, factory reset and other SFP ports were tried. Another user returned the switch after failing to link it to…
Cisco-compatible CWDM SFP modules that had worked in Dell PowerConnect 6024 and 6224 switches produced a transmit failure error in a PowerConnect 8024F, presumably because the 8024F ports are SFP+. The poster considered Finisar FWLF1524P2Vxx modules but wanted confirmation from someone with a…
After a complete power loss a Dell R740 with a four-port Broadcom NDC (2x SFP+, 2x 1GbE) booted normally but the fibre SFP+ modules stayed unpowered and disconnected; a reboot did not help and only physically removing and reinserting the modules restored them. Dell support pointed at drivers and…
A UCG-Fiber used a UACC-CM-RJ45-MG 10GBASE-T module (port 6, later port 7) to reach a Zyxel XS1930. Whenever the copper cable was disconnected for more than about 40 s or the Zyxel rebooted, the link never came back until the module was pulled for a minute or the gateway rebooted; forcing 10G or 1G…
An out-of-the-box ES-48-Lite (1.9.3) was connected to an EdgeRouter Infinity ER-8-XG (2.0.9-hotfix.2) with a UF-RJ45-10G module on each side and a Cat6 cable. A laptop on the switch obtained a DHCP lease from the router only after about a minute and then could not reach the router or the internet…
Between VxRail Dell S5212F-ON TOR switches and Cisco C9500-48Y4C switches, FS.com SFP28 DACs behaved inconsistently: a 5 m cable custom-coded Cisco on one end and Dell on the other came Line Up, Protocol down; a 2 m Cisco/Cisco-coded cable linked; a 3 m cable would not link even with the 2 m…
A QSFP28 100 Gb DAC supplied by Supermicro linked two Dell S5248F-ON (OS10 10.4.3.6) switches fine, but between the Dell and a Supermicro XEM-100 the port showed up, line protocol is down. Multiple FEC and negotiation combinations were tried. The thread received no answers. Hardware involved: Dell…
A short no-name DAC between a UDM SE and a Minisforum MS-01 had worked for months; a new 30 m Ubiquiti UACC-AOC-SFP10-30M active optical cable was recognised by the UDM SE (vendor, part, serial, temperrature, power visible) but no link came up and the SFP port log showed an SFP EEPROM error; on…
The poster wanted to connect a UDM SE (10G SFP+) to an Enterprise XG 24 switch (25G SFP28) and asked whether an SFP+ DAC would work with the SFP28 port falling back to 10G, or whether an SFP28 DAC was preferable. The concern was whether the SFP28 cage would fall back to 10G with an ordinary SFP+…
A UDM Pro (port 11 set to 1G) and a US-16-150W (port 17) connected by a 1 m Ubiquiti DAC (UDC-1) did not talk: the switch showed a link light, the UDM Pro showed nothing. Setting both sides to 1G and rebooting both devices did not help; reversing the cable and removing the parallel copper uplink…
An ADDON JD097C-AO SFP+ DAC worked between two US-48-500W (firmware 3.3.11.3850) but not from a US-48-500W to a US-16-XG (3.7.39.6089): no link lights on either side and forcing 10G made no difference, although mca-dump on the XG showed the module fully parsed (sfpfound true, vendor ADDON, part…
An EdgeRouter 4 (EdgeOS 1.10.0) with the GPON SFP taken from a Bell Home Hub 3000 (Huawei MA5671A, SC connector, DDM readable: 50.9 C, 3.25 V, 8.87 mA, TX 1.36 mW, RX 0.02 mW) logged kernel: Failed to read SFP EEPROM1 at byte 0 val -11!! twelve times a minute although the internet worked. Removing…
On two sites a UNAS Pro (UniFi RJ45 SFP+ module) and a UNVR (UniFi fibre SFP+ module) dropped to 1G after every firmware update or power cycle; rebooting the device, the port or the switch did not help, only physically pulling and reinserting the module (or reseating the fibre) restored an…
After moving a Bell fibre connection from an ER-X to an ER-4 with the ISP's Alcatel-Lucent/Nokia GPON SFP (3FE46541AA / G-010S-P) plugged directly into eth3, the WAN dropped every 3 to 60 minutes; syslog had hundreds of kernel: Failed to read SFP EEPROM1 at byte 0 val -6!! entries and SFP module…
A MikroTik RB4011 connected with an S+DA0001 DAC to a CRS106-1C-5S and a CRS112-8G-IN (all default configuration apart from IP addresses) had no connectivity over the SFP link. The RB4011 SFP+ cage is documented to accept onyl active direct-attach cables, so a passive twinax between it and the two…
A new UDM Pro replaced a USG-3; plugging its LAN SFP+ port into the free SFP port of a UniFi Switch 24 with a known-good SFP+ DAC (taken from a working switch-to-switch link) gave no link on either UDM Pro port, and manually setting the UDM Pro port to 1 Gbps did not help. Several other users…
After UniFi Network 10.0.140 / switch firmware 7.2.123 several operators saw SFP+ ports (UI optics, UACC-OM-MM-10G-D, MikroTik XS+DA0001 DACs, UACC-CM-RJ45-MG copper modules) flapping on US-XG-16, USW Pro Max, UDM Pro and USW-24-Pro units, with STP State Flapping alerts, ports blocked, and switches…
Newly delivered EdgeSwitch ES-24 units linked to each other over gigabit SX SFPs, but the same modules (HP J4858B, J4858A, Avago AFBR-57M5APZ, Avaya AFBR5715PZ, Cisco) would not link ES-24 to HP ProCurve (four models) or Netgear (two models): the ES-24 showed a link light, the other side did not…
With a CSS326-24G-2S+ (SwOS 2.6) and a server with an Intel 82599 card, two different S+DA0001 DACs and two Intel cards never linked; two CSS326 switches connected by DAC only achieved 1 Gbps. A later reader on SwOS 2.12 with an 82599 reported the same. No solution was posted. Hardware involved…
After upgrading a CRS309-1G-8S+IN from RouterOS 6.48.6 to 7.14.1 (and 7.15beta8), ports 5 and 7 with 10Gtek ASF-GE-T (FTRJ8519P1BNL-PT) copper SFPs showed sfp-rx-loss: yes and no-link when auto-negotiation was enabled; disabling auto-negotiation and forcing 1G full duplex restored the link…
A user with a MikroTik GPON ONU SFP module in a RouterBOARD facing a FiberLink OLT saw the interface as registered but the module serial never appeared in the OLT for provisioning. The thread turned into a reliability report: an operator lost every deployed MikroTik GPON module within two months of…
With auto-negotiation on, CRS317 and CRS326 SFP+ interfaces ran at 10G; with auto-negotiation=no, speed=10Gbps and full-duplex=yes the log still reported link up (speed 1G, full duplex) regardless of the advertise settings. On a CCR1009 the same configuration produced no-link instead, showing that…
Hi, I am looking for a solution for working with OSFP-XD 1.6 (and higher) transceivers. Your documentation states that CodingBox supports various hardware programmer solutions. Are there plans to develop a programmer for the XD format, and if so, what is the estimated timeframe for the…
A MikroTik CRS312-4C+8XG (RouterOS 7.13.4) and a Ubiquiti USW-Pro-48 (6.6.61) over 20 m OM3 with SR 850 nm SFP+ optics would only negotiate 1G full duplex; 10G attempts failed with no link and occasional Rx Fault on the UniFi side. Several fibre and transceiver combinations were tested and RouterOS…
Contradicting MikroTik's documented advice to force 1G full duplex when using 1G optics in SFP+ ports, a Netpower Lite 7R linked to an RBFTC11 only with auto-negotiation (forced 1G gave link up but zero received packets), while the same Netpower to a CRS328-4C-20S-4S+ had heavy packet loss and FCS…
Replacing the ISP ONU with a Baudcom DB-1234-SFM GPON SFP stick in a hEX S: the stick registered with the OLT and obtained an IP with the spoofed MAC, but with sfp1 as WAN pings returned network unreachable, although the same configuration on ether1 (behind the ISP ONU) worked and Winbox showed no…
Two Solid Optics SFP-H25GB-CU5M SFP28 DACs between a MikroTik CCR2004-1G-12S+2XS and an FS S5860-20SQ switch produced status: no-link on sfp28-1 and sfp28-2 with auto-negotiation off, 25 Gbps, full duplex, FEC91 and no flow control; RouterOS 7.8rc1 was tried on vendor advice. The modules were…
A MikroTik CSS610-8G-2S+IN showed an active SFP+ link, but Intel X520-DA1/DA2 NICs (Windows, Linux, ESXi) reported no link, reproducibly across multiple transceiver pairs, DACs and two cards. Firmware 2.12, 2.13rc6, 2.13rc12, 2.13rc25 and the final 2.13 were tested. Hardware involved: MikroTik…
A CRS326-24G-2S+RM and a CCR1009-7G-1C-1S+PC connected with a MikroTik SplusDA0001 SFP+ DAC only linked at 1 Gbps; enabling 10G dropped the link, and the CRS326 in SwOS did not even offer a 10G option. The poster needed SwOS for harrdware LACP. RouterOS/SwOS updates, supout files, and a replacement…
A CSS326 (SwOS 2.12) uplinked to an RB4011 throuhg an FS.com 10G active DAC accumulated Rx MAC errors, Rx FCS errors and Tx pauses. Cleaning the DAC connectosr did not help, and the poster asked whether SwOS had SFP+ bugs. Hardware involved: MikroTik CSS326-24G-2S+, MikroTik RB4011, FS.com 10G…
The poster wanted to use a MikroTik XS+DA0001 passive DAC between the 1G SFP port of an RB3011 and an SFP+ port of a CRS309 and asked whether a passive cable can bridge different SFP generations. The RB3011 SFP cage is 1G only while the CRS309 cage is SFP+ (10G), and a passive DAC has no active…
A FLYPRO SFP-1G-CS-100M 1000BASE-T module in a MikroTik CRS112-8P-4S (RouterOS 6.47.10) was detected but reported no-link with sfp-rx-loss: yes, whatever the far end (MikroTik LHG/RB750Gr3, Ubiquiti, Cisco). Fixed 1G speeds, other module units and rebootts were tried; only a Ubiquiti switch linked…
SFP+ DACs linked MikroTik-to-MikroTik and OLT-to-OLT, but between a V-SOL EPON OLT 16008D and a CCR2004-1G-12S+2XS or CRS326-24G-2S+RM the OLT reported the interface as disconnected. The same DACs were recognised on both platforms, so the poster suspected a cross-vendor auto-negotiation or…
On a CRS226-24G-S2+RM (RouterOS 6.42.11 long-term) the SFP+ port stayed at no link, not running, slave after a power loss, while software reboots were fine; disabling and re-enabling the interface fixed it manually. The problematic module was a Huawei MA5671A GPON SFP, other SFPs behaved, and the…
After upgrading a CRS305-1G-4S+ to SwOS 2.12, SFP-GE-T 1000BASE-T copper SFPs stopped linking although the switch still identified them in the SFP tab; the same modules kept working on a CRS317-1G-16S+ with the same firmware. Modules inserted before the upgrade continued to work, modules inserted…
On a CRS326-24G-2S+ with RouterOS 7.7 three third-party 1G RJ45 SFPs failed: an HP 453156-001 (FCLF-8521-3-HP) showed no-link with auto-negotiation: failed, a Foundry E1MG-TX showed no-link with sfp-rx-loss: yes even with manual speed, and a Ubiquiti UF-RJ45-1G also stayed at no-link. Hardware…
A MikroTik CCR1036-8G-2S+ with S-31DLC20D 1.25G single-mode SFPs reported link OK but no traffic flowed; TX power was blank and RX was -9 dBm. The identical module on the same fibre worked in a CCR1036-12G-4S. Port disable/enable, forcing 1G full duplex on both ends and support tickets did not…
Two FS.com 1G BiDi SFPs (1490/1310 and 1310/1490 nm) in a MikroTik CRS326-24G-2S+ running SwOS 2.9 detected incoming light around -6 dBm but never established a link; the same optics linked on a Netgear switch. The poster asked whether a manual speed setting was needed and whether RouterOS would…
A first-time SFP+ deployment between a UniFi 16XG switch and a Tehuti Networks TN9310 SFP+ adapter, with transceivers the reseller called compatible, produced an Rx fault indication in the UniFi controller. Swapping the fibre ends (polarity) did not help. Hardware involved: Ubiquiti US-16-XG…
FS.com 40 km 1550 nm SFP+ modules (item 11592) showed their information in a MikroTik CCR1016 but never linked in the SFP+ ports, whatever the auto-negotiation, 1G/10G speed or flow-control settings; standard 10G modules (item 29851) worked in the same ports, and the 40 km modules ran at 1G in…
A MikroTik CSS610-8P-2S+ (SwOS Lite) needed to connect its SFP+ ports to a Cisco Nexus 5596UP. The ports showed the transceivers in the web UI but no link, after trying several fibre cables and transceivers. The switch web UI listed vendor and type for each module, yet the port stayed at no-link…
A pfSense router on a Supermicro R210 II with an AOC-STGN-i2S (82599-based X520 clone) was connected throguh an FS.com SFP+-to-RJ45 module to a cable modem with a 2.5 Gbps port. No link negotiation happened; pfSense offered only auto and 10G speeds and never 2.5G. Hardware involved: Supermicro…
