Will adding switch extend my ethernet cable?

Solution 1:

The length restriction is related to collision detection.

As each switch port is a collision domain, you can use a switch to extend the distance and get more than 100m.

Just like this :

A ------------------------Switch ----------------------------B 

           100m                                100m

You can continue extending the distance using another switch from B to another destination and so on, however it is recommended no extending more than 7 switches (7 hops).

The 7 hops limitation is related to the Spanning Tree Protocol. This protocol is designed to control and prevent the creation of closed loops in a switching network.

In a case where you will need to use 7 or more switches, then it's better to put some fiber optic from initial source to final destination and use only one switch.