Switching

Hi guys.

I have a problem between my Palp Alto an my mx 10003.

When i boot the Palo Alto, the link on my mx goes down, thats correct.

When the Palo comes up after a few minutes, the port on my mx comming up for 4 minutes.

After this time, the interface on my mx goes down.

When i disable/ enable the interface the port goes up and everything works fine.

I do not why and i can not find something in the www.

Thanks for your help everybode

what do the logs show on the MX? 

Get error counts, packet drops, and physical layer details:
show interfaces <interface-name>

Clear the interface and recreate the issue:
clear interfaces statistics <interface> 
(wait ~4 mins)
show interfaces statistics <interface>

Take a look at general logs: 
show log messages | last 100 

Check for STP or MAC Flapping:
show ethernet-switching table interface <interface>
show spanning-tree interface <interface>