[c-nsp] Windows Vista, Gratuitous ARP and DHCP conflicts

[Kurt Bales]

Hey Guys,

Has anyone else noticed an increase in "Gratuitous ARP" entries under "sh ip
dhcp conflict" lately?

We serve Customer addresses (for better or worse!) via DHCP in some network
designs. The DHCP server is running on the local Cisco Device in the area
(usually an 1811). Lately we have noticed a large number of "conflicts"
listed with "Gratuitous ARP" as the reason. 9 times out of 10 has shown the
offending machine to be a Windows Vista install.

Does anyone know why this is happening, or a way we can combat against it?
We are moving our network away from DHCP addressing for customers, but this
is a slow process. Is there a method to alert when the number of conflicts
reaches a threshold?

Regards,

Kurt Bales