It sounds like something is causing unicast flooding on your switch. There are several things that can cause this including overflow of the cam, or assymetric traffic flows. In assymetric traffic flows frequently there are two switches on a VLAN. A host is connected to switch A and sends its traffic out through its connection to switch A. The traffic gets to the destination and the response comes back through switch B. Since the outbound traffic from the host is going through switch A its cam knows the mac address. But since frames from the host are not going through switch B its cam does not learn the mac. And therefore when the response traffic comes through switch B does not have a mac address associated with the IP address and will flood the packet to all ports in the VLAN. It is my guess that this is what is happening in your situation.
 you asked the question about unicast flooding while I was typing my answer.
And yes I believe that your situation may well be due to unicast flooding.
This is actually a pretty cool feature, i didn't even know it existed until I was looking for a solution to advertise a subnet (prefix in BGP talk), only if a certain condition existed. This is exactly what conditional advertisements does
j ai une question j ai achete un routeur cisco 887VA-k9 , je le configuré avec la configuration ci- dessous
si je le lier avec mon pc portable sur l un de ses ports directement ça marche toute est bien ( la connexion internet + m...
Attached policy provides CLI access to the Cisco 4G router over text messaging. Two files are in the attached .tar file:
2. PDF with instructions on how to load and use the .tcl file.