A D-Link DES-3200-28 B1 switch logged DDM Port X optic module RX power exceeded the low warning/alarm threshold; the optical level looked abnormally low in the switch although the module measured fine when tested standalone. Hardware involved: D-Link DES-3200-28 B1, DDM-capable SFP. Reported…
On Debian 8.11 (kernel 3.16) the poster ran ethtool -m on a Mellanox MT26448 adapter to read optical diagnostics (TX/RX power, temperature, voltage, thresholds) and got Cannot get module EEPROM information: Input/output error. Hardware involved: Mellanox MT26448 ConnectX-2, SFP+ optic with DDM…
Small office, we are dropping the ISP-supplied box and terminating the fibre straight on the router. The handoff is AON, the provider only asks for a VLAN tag, no PPPoE and no ONT registration. What is in the rack: TP-Link ER7412-M2 V1, firmware 1.0.1, fibre into port 11 (SFP WAN) a TP-Link…
A QSFPTEK 10GBASE-T SFP+ module installed in port ix1 of a passively cooled Netgate 6100 reported 73 C through DDM although the room was at 20 C; the module is specified for 0-70 C and up to 2.5 W. The poster asked for known-good RJ45 SFP+ modules that stay within spec. Hardware involved: Netgate…
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…
The poster wanted to dump the EEPROM of a QSFP+ transceiver plugged into an Intel XL710-QDA1 and ideally read live DDM values such as received optical power, as they were used to doing with SFP modules on other adatpers. With i40e 2.0.23 and firmware 5.05 0x800028a2 1.1568.0, ethtool -m eth0…
On Ubuntu 18.04 (kernel 5.4.0, ethtool 5.3, i40e 2.8.20-k) the poster used 25G XXV710-based NICs bought from FS.com (FS part XXV710AM2-F2, Intel XXV710 chipset). Link and error-free wire-speed traffic worked, but reading a transceiver's DMI data with sudo ethtool -m enp4s0f0 failed with "Cannot get…
A Cisco Catalyst 3850-24XS with an SFP-10G-LR (1310 nm) connects over a single-mode cross-connect to a Tier-1 carrier's layer-2 DWDM equipment in the same data center. When the carrier shuts the circuit down, TenGigabitEthernet2/0/23 goes 'down, line protocol is down (notconnect)' yet 'show…
