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…
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+…
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…
With two dual-port Mellanox ConnectX-4 cards, a MikroTik SFP+ switch, 1 m OM4 patches and mixed 10G/25G transceivers from several vendors, one NIC port showed link UP but got no DHCP and could not route, 25G transceivers negotiated only 1G, and previously stable 10G links dropped intermittently…
Before deployment the poster asked for a certified or tested SFP28 DAC to connect an HPE FlexFabric 5950 with an SFP28 card to a dual-port Mellanox MCX4121A-ACAT (ConnectX-4 Lx), and for any documentation of that pairing. Hardware involved: HPE FlexFabric 5950, Mellanox MCX4121A-ACAT, SFP28 DAC…
Standing up 25G uplinks from a QFX5120-48Y towards a second switch and a couple of new servers. Before I hand the segment over I want the link settings written down properly, and I cannot find where auto-negotiation lives on these ports. Juniper QFX5120-48Y 25G optics in the SFP28 cages et…
A Mellanox ConnectX-4 Lx (MCX4121A-ACAAx, firmware 14.32.1900) in a Ryzen desktop (Fedora 41 and Windows 10) detected the interface but reported Cable is unplugged with two FS.com SFP28-25GLR-31 modules and a 40 m single-mode LC duplex patch; a MikroTik router recognised the same optics. The poster…
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 are collapsing two aggregation rows onto FortiSwitch, and the last piece is a 25G interconnect between an FS2048 and an FS648 in adjacent racks. Everything else in the design came up on the first attempt; this one link refuses to. FortiSwitch 2048, 25G front-panel port FortiSwitch 648, 25G…
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…
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…
A brand-new retail Intel E810-XXVDA2 on Windows Server 2022 (Intel driver 1.12.164.0 from release package 28) was connected to an SFP28 port of a Ubiquiti USW-Pro-Aggregation switch. With an SFP28 DAC the link came up at 25G immediately, but with SFP28 optical transceivers (Ubiquiti…
The poster connects a Cisco Catalyst C9300X-24Y to a FortiGate firewall with a 25G SFP-H25G-CU2M DAC. Whenever the DAC is inserted the switch logs '%PLATFORMPM-6-MODULEINSERTED: SFP module inserted with interface name Twe1/0/23' followed by '%PLATFORMPM-6-DIFFERENTMODULEINSERTED: Warning: SFP…
The poster was connecting a Cisco Nexus 93180YC-FX to an Arista 7050SX3 with a 25G AOC sold as Cisco/Arista compatible. The Nexus detects the transceiver, but 'show interface status' reports the port as not connected. A 10G AOC from the same vendor works fine between the two switches, and the same…
The poster, a new owner of a Cisco Nexus 93180YC-EX running NX-OS 7.0(3)I4(7), cannot bring up any 25G link. ipolex SFP28 DAC cables are recognized ('type is SFP-H25GB-CU1M', 'name is OEM', 'part number is SFP-H25G-CU1M', 'nominal bitrate is 25500 MBit/sec', 'DOM is not supported') but the port…
The poster connected a Dell server to a Cisco Catalyst C9500-48Y4C (IOS XE 17.9.3) using a Dell L56SF018-SD-R 3 m DAC (DAC-SFP-3M). The cable is not in Cisco's optics compatibility matrix, and 'show interface status' shows port TwentyFiveGigE1/0/35 as err-disabled. Logging shows…
