Svyatoslav,
What kinds of Windows computers do you have? Are you running NT domains? If you have any Windows NT 4.0 Servers, or Windows 2000 or XP Servers, then you can set up Windows Internet Name Service (WINS) on one or two of them. Then configure your desktop computers to register with one or both of them. This is much easier than using LMHOSTS and HOSTS files on each computer, especially in a dynamic environment.
If you are using Microsoft's DHCP services, then you can send the WINS server IP addresses to the desktop computers along with their IP addresses. As a DHCP option, WINS servers are option 044 I think, NBNS servers (NBNS = NetBIOS Name Servers; Windows computers use NetBIOS names). You will also need to specify a NetBIOS node type, which is DHCP option 046 I think. Usually the best choice is 0x8 which specifies "h-node" or "hybrid node". If you read up on the different node types (there are 4 of them), you will figure out that "hybrid" is the one most people choose. It is generally the most efficient.
If you are not using Microsoft DNS in-house yet, you can also set up DNS on the same servers that are running WINS. And you can link DNS to WINS, too. But that is a story for another time...
Older Windows networking runs into these complications when you have multiple IP subnets, because the underlying foundation is NetBIOS, which is non-routable. Microsoft has had to develop ways and work-arounds to get NetBIOS to run over TCP/IP. Newer Windows (2000, XP) can do it all through DNS I think, but the desktop computers have to register with the Microsoft DNS servers on your network for it to work. Oh, I almost forgot, you can also send DNS server IP addresses to the desktop computers using DHCP.
The symptoms you described are typical of Microsoft name resolution issues. It's not a Cisco problem.
Hope this helps. (MCSE 4.0, MCP+I)
