How should the network wire be crimped so that both LEDs are not active, but data is being transmitted?

Question

Computer networks

The right LED is understandable. What's with the left? The question is asked in continuation of the question Mikrotik and ipmi. Chiadnt?

Answer 1

Diodes ignite the driver. And the cable must be crimped according to the standard.
The card driver checks the MII-transmitter chip, and on a signal from it (on interruption), lights up the appropriate combination of diodes. If the diodes do not burn, then there is simply no link.
There are MII microcircuits in which the combination of diodes is selected by default, and you don’t even need to control the light bulbs, just activate the link, the rest is done by the hardware by default. But you can also blink from the driver :-)
But in any case, the bulbs have nothing to do with the cable. And if someone tells you that there is such a "magic" crimp combination, then he is just fooling you!

Answer 2

Diodes ignite the driver.

This is not true. Diodes are lit by a physical layer chip. The driver can only set the mode of operation of these diodes, and even then not always.
To force the interface to switch to 10 Mbit mode, you can take a cable longer than 100 m, but the Link / Act diode will still light / blink when there is a link / data transfer. To disable it, you will need to patch the driver or the contents of the EEPROM chip, if it exists.

Answer 3

Something is wrong with the cable.
I will assume that the port there is gigabit, but it works at 100. Apparently one of the pairs (RX or TX) is damaged and for some reason the microcircuit uses lines for gigabit (blue or brown pairs).