That's the way ethernet work in half duplex. You cannot transmit or receive at the same time. If two machines try to send at the same time collision occurs and all machine back off for some time before sending the frames again.
Please go to google and find out the ethernet operation links.
We are pleased to announce availability of Beta software for 16.6.3. 16.6.3 will be the second rebuild on the 16.6 release train targeted towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are looking for early feedback from custome...