I'm setting up a new data center with two Nexus 7000 and one Nexus 5000 . The 5000 is connected to both 7000s using a vPC ( all is done by the book and the vPC is working very well).
If I enable any VLAN interface on the 5000 then I start getting a duplicate IP address warning ( the IP address of the VLAN interface ) :
%ARP-2-DUP_SRC_IP: arp  Source address of packet received from 000d.ecf2.8dbc on Vlan90(port-channel4043) is duplicate of local
It seems that the gratuitous arp requests for the local address are getting looped back to the 5000 over the vPC !!
I noticed that the issue only happens when the DHCP feature is enabled on the Nexus 7000s ...
Any help is really appreciated ....