If your router or PC reports Speed 100.100 and you pay for 500 Mbps Internet, you are losing money. Here is your fix protocol:
PLC (Programmable Logic Controller) systems in manufacturing plants often rely on legacy Fieldbus-to-Ethernet converters. Many of these devices are locked to 100 Mbps Full Duplex. Attempting to auto-negotiate to 1 Gbps will fail, causing link flaps. Manually setting Speed 100.100 on the switch port ensures rock-solid stability for critical machinery. Speed 100.100
In the context of computer networking and cloud computing, "Speed 100.100" almost certainly refers to the Amazon Time Sync Service, a feature provided within Amazon Web Services (AWS). If your router or PC reports Speed 100
Will Speed 100.100 ever disappear? Unlikely. In the same way that 10 Mbps Half Duplex stubbornly survives in elevator controllers and building automation, 100 Mbps Full Duplex will remain a bedrock standard for the next decade. If the CLI returns "100Mb/s" but the GUI says "100
We are seeing a resurgence in interest from:
If your system stubbornly reports Speed 100.100, do not trust the GUI. Use the command line to see the actual negotiated link.
networksetup -listallhardwareports then ifconfig en0 | grep mediamii-tool eth0 or ethtool eth0 | grep Speed
If the CLI returns "100Mb/s" but the GUI says "100.100," your OS vendor needs to update their rendering library. If the CLI says "10Mb/s" or "Down," you have a hardware fault.