I have a computer that hosts virtual machines. This computer has TWO gigabit Ethernet cards.
Every time I connect the cable to the second NIC, the speed of the first low to 100mbit, even if it looks like a gigabit.
The second Ethernet card is not connected to the same network and is connected to 100mbit devices.
It seems that Ubuntu replicates in some way, the behavior of the second card in the first …
The two interfaces are functional and serve their purpose, only the speed of the year 2000 bothers me.