I have a few Vista Enterprise and they are causing a lot of headaches. I found out that they are doing DHCPv6 Renew every now and then which is not actually a problem but the request comes flooding by the thousands within a few seconds (as shown below when captured with wireshark) causing a network flood.
fe80::b589:8846:69f9:6f3d ff02::1:2 DHCPv6 196 Renew XID: 0x1c110e CID: 000100011b199761001a4b3f6fba IAA: 2001:x:x:::aae3
Only happened on Vista. There is nothing else to update on the system and could not find solution to this. The only way to stop this is to disable IPv6 on the system which is not actually a solution. Appreciate any help.