Hi René and Team Networklessons

when use this command mean restart eigrp or reset could you detail ?

R1#clear ip eigrp neighbors

Hello Bunleang

This command will cause all EIGRP neighbour relationships to drop. This will also cause all associated topology table entries to be removed. Once this is done, new EIGRP neighbour relationships will be formed from scratch. The EIGRP process is not restarted, in the sense where it is disabled and enabled again, but it is reset, meaning that all routing information is removed and relearned from scratch.

I hope this has been helpful!