quote:
Are you using DHCP or statically assigned IP addresses?

We use static IP

quote:
If you have WINS servers running, why do you not have the clients configured to use them?

We have some reason:
- We afraid it will consuming bandwidth
- We don't want them to see other site computers easily

quote:

What domain model do you have implemented? Please describe in detail.

Sorry, I don't get what do you mean

quote:
How many subnets?
Actually four (not including router), but in this example i only mention 2 (the rest i guess i can find out myself if these 2 can be solved)

quote:

Do you have the routers configured to block broadcast packets?

We don't block broadcast packet but we block some port (i don't know broadcast packet use which port)