How is the transmission speed negotiation in 100Mbps \ 1000Mbps networks?

Question

Computer networks

The simplest local network is a computer with a 1Gb network card <> a 1Gb unmanaged switch <> a 100Mb unmanaged switch <> a computer with a 100Mb network.
How do computers establish a connection and negotiate at what speed data is transferred? Will there be packet loss in this configuration?

Answer 1

https://en.m.wikipedia.org/wiki/Autonegotiation

Answer 2

How do computers establish a connection and negotiate at what speed data is transferred?

Because we have hubs that have the slowest port running at 100 Mbps, will reduce the speed to the speed of the slowest port, the total speed will be 100 Mbps. Hubs are stupid, therefore they have no agreement, except for "we work at the speed of the slowest port".

Answer 3

There are several levels.
1. Port speed.
2. Data transfer rate.
For the first one, there are special mechanisms, Autonegotiation, an important point, the link speed will not always be the maximum possible, and in some conditions it needs to be artificially lowered in order to get a stable connection.
For the second. If we are talking about udp, then the speed is not regulated in any way, with which one gives, the other receives with it. If it cannot accept the package is lost. In the case of TCP, look towards TCP windows size, there is a special mechanism for adjusting the speed to the channel.