Command delay 100 under interface vlan (SWITCH)

Hi i have a question
The command - delay100 - under interface vlan XYZ on the switch what does it mean ?
And why i implement this command

Hello Ugo

Interfaces on switches have several administrative parameters that can be used to adjust the operation of dynamic routing protocols. Among them is the delay parameter. You can adjust this parameter on the interface and it will affect the way that EIGRP calculates the metric. By making changes to the delay parameter you are not making any physical changes to the way the interface operates. You are not actually increasing the delay of the sending of frames on that interface. It is essentially a label used to allow EIGRP to calculate the metric.

In this way, you can fine tune the way EIGRP function in a network making certain paths cost more and others cost less. Bandwidth is another administrative parameter that is used by both EIGRP and OSPF.

Best practice dictates that you should use the delay parameter to affect EIGRP routing decisions and the bandwidth parameter top affect OSPF. Using both to adjust EIGRP can become complicated and tricky and may provide unpredictable results.

I hope this has been helpful!