Some time ago nearly all workstations in our team (Windows XP SP2) exhibited intermittend but frequent delays when accessing shares on the network. Typically the first access to a share which hadn't been accessed for some time resulted in a nearly frozen workstation for up to 30 seconds. Then everything started working fine again.

Using TCPView from Sysinternals I saw that during this delays there was a connection to the netbios-ssn port on the file server which was in state SYN_SENT.

First try:

Disable NetBIOS over TCP/IP for the intranet network adapter.

Problem solved, but I didn't like to manipulate our centrally managed network configuration for the intranet.

Second try:

Disable NetBIOS over TCP/IP only for the VMWare network adapter (VMNet1 used for host only communications).

Problem solved again!

My questions:

• Why does NetBIOS over TCP/IP on one network adapter disturb NetBIOS over TCP/IP on another network adapter?
• Is this problem specific to VMWare network adapters?
• Has anybody else seen this phenomen?

Additional information:

• VMWare Workstation version 6.0.3
• At the time I started seriously analysing the problem it was no more possible to find out what had been changed to our systems at the time the problems started.