An HPE FlexFabric 5950 48SFP28 8QSFP28 (JH402A) always downgrades an HPE JH419A 100G QSFP28 LC SWDM4 transceiver to 40G and never brings it up at full speed. Why?
We are handing a 100G circuit off to a core router through a leased optical transport system, and the port on our side refuses to come up. The same pair of modules links instantly on the bench, which is what makes this so irritating. Wedge100BF-32X (wedge100bf32x) running SONiC InnoLight…
We are wiring an FPGA capture card into an existing server and I am stuck at the very first step: the port simply never comes up. The setup: Mellanox MCX414-GCAT (ConnectX-4 EN, QSFP28, 50GbE capable) in the host FS Q-8LCA020 breakout AOC, QSFP+ on one end, eight LC ends on the other FPGA card on…
On a Mellanox SN2410 (MLNX-OS 3.6.4112) a 100G port connected to a Chelsio adapter through a 2 m unequalised QSFP copper cable would not link when FEC was disabled; no HSS lane signal was detected on the adapter side. The poster required FEC-off operaation and asked whether the switch supports it…
Mellanox-branded Q-4S28AO03 3 m QSFP28 AOC 1x4 breakout cables (100G with FEC) that worked under Onyx 3.9.1908 stopped linking after an upgrade to Onyx 3.10.x. The ports reported Cable speed not enabled and, with auto speed, Negotiation failure; supported speeds showed 1G/10G/25G but the actual…
Adding a 100G link between two racks on an X690 that has been quietly doing 10G access work for a couple of years. The uplink cage will not take the speed at all. ExtremeSwitching X690-48x-2q-4c 1 m QSFP28 direct attach cable, Q28+CR41m port 57, one of the QSFP28 uplink cages The cable comes up as…
Replacing a customer's incumbent aggregation pair with CloudEngine kit, and the single link that refuses to come up is the 100GE feed into their packet broker. Everything else on the switch went in without drama. Huawei CloudEngine 6800, 100GE port 100GBASE-SR4 QSFP28 modules, Huawei parts, one at…
We are building out two racks and the switching is settled: a pair of M4500-48XF8C as the leaves with M4350 underneath. What is not settled is the optics BOM. NETGEAR does not put its own label on 25G or 100G modules, and I would rather not discover after delivery that the SFP28 ports dislike what…
We run a pair of racks that hand off to a carrier-facing Cisco NCS, and one of the 100G server uplinks has never come up since the build. Same result after moving the server to another cabinet with a different patch panel, so I have stopped treating it as a one-off. Supermicro server…
I am wiring per-port optical telemetry into monitoring for a couple of Nexus 9000 fabrics. Collection runs through NAPALM, and the getter I lean on is getoptics(). Nexus 9000 leaf and spine pairs QSFP-100G-CWDM4 modules on the fabric links NAPALM with the nxosssh driver, SSH transport, no NX-API…
We run a three-node cluster with the nodes cabled directly to each other over 100G DAC, no switch in the path, and the interfaces put into a broadcast bond so replication traffic has its own fabric. Before I put real load on it I wanted a baseline, and the numbers do not agree with each other. 3x…
We are reusing a pile of 10G optics on a whitebox switch running SONiC, so a few QSFP28 cages are fitted with QSA-style adapters (10GTek QSA-100A) carrying plain 10G SFP+ modules. Mechanically and electrically this is fine. The management side is where it falls apart. switch: 1U whitebox, SONiC…
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…
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…
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 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…
