3Com Baseline Switch 2952 Problem

[EsperIT]

Dear ,

I have some problem about 3Com Baseline Switch 2952, I add a HyperV server plug into the switch, I notice that  the Guest Server in the HyperV host can not access the other PC and internet sometime. However, the Hyper V host can access both the Internet and the Guest Server. I try to add a normal switch (8 port unmanaged) to plug this server, it work for two month with no any problem.

Do this switch has some setting in default that can block the high usage traffic? How can I set it? Thanks.