Blocking a MAC address

[rite2anil]

Hi All,

I have a cisco2960 with c2960-lanbasek9-mz.122-50.SE4 imagebase.This switch is connected with 3 unmanaged switches.Though 2960 is managed and only a single vlan is given accessed to connected other unmanaged switches.Problem is this, if at user end, a laptop is connected ( Microsoft Vista OS) and its IPv6 is checked in the LAN properties settings then the laptop's IP address changed from our VLAN to 192.168.100.x series and due to this other connected user's DNS addresses become changed.

Hence I want to block this IP or its MAC on Cisco 2960. Is there any solution?

Regards,

Anil K.

[cadet alain]

Hi,

Problem is this, if at user end, a laptop is connected ( Microsoft Vista  OS) and its IPv6 is checked in the LAN properties settings then the  laptop's IP address changed from our VLAN to 192.168.100.x series and  due to this other connected user's DNS addresses become changed.

This is not very clear for me , could you explain more thoroughly please.

Regards.

Alain