The core switch of our company is Catalyst 6509 with SUP2. Last week we change to new Catalyst 6509-E with SUP2T. The configuration of new core switch are almost same with old switch, we have not enable ipv6 routing. But after we change core switch to new core switch, some WIN7 client fail to get IP address from DHCP server. These WIN7 client enable both ipv6 & ipv4 and both configure automatic to get IP address. After disable ipv6 protocol at WIN7 client, then these client can get ipv4 IP address from DHCP server.... Please help to mention me how to resolve this problem if not disable ipv6 at WIN7 client?
Not sure if this is happy eyeballs issue where all latest devices have inbuilt feature to prefer ipv6 over ipv4 for the smoother migration to ipv6. However when there is no ipv6 reachability it will fallback to ipv4. can u try to disable ipv6 router advertisement on the switch lan connecting to the win7 client? (RA works similar to DHCPv6 with some issues assigning DNS).
i think the commands is something like 'ipv6 nd suppress ra".
Also check if the LAN interface on the switch has ipv6 disabled.
Let me know.
The command for my Catalyst6509 is "ipv6 nd ra suppress all". If no ipv6 enable on the interface, is the ipv6 ra still work if we dows not disable it?