Strange Scanario Betwen switches, need Help Urgent

[Abubakar Siddique]

Hello Friends, i have no idea whats going on here. lol i have deployed network of 6 switches i have created trunks between them , one switch is core which is 3850, the rest are 2960, trunking is fine , they are all in the same domain. vtp server is  3850, the resy are client mode, i have created SVIs,.

After this tried to ping from core to other switches, the ping was succesfull and there was no delay at all, then i tried again after 5-10 mins i could only ping 2 switches and couldnt ping the rest. then i plugged in one of the client switches. i started the ping it was successfull but again after 5 minutes there was zero responce when i tried to ping the other switches only SVi to SVI? have never faced such issue in my life. May be you guys know whats going on here? 

I have attached the ping status in the files . Kindly let me know whats wrong .

[network_guy]

Can you post the configuration of the switches? There's not much to work with from the ping results..

[Julio E. Moisa]

Hi

The new switches are set up as vtp server by default, a good practice before to be installed on the networks is change them to transparent or client mode in order to avoid any impact on the network. You could verify if the vlans are being propagated through the trunk interface from the server to other switches, also verify if the root bridge for the vlans is always the core. 

Hope it is useful

:-)