I have two clients, both are using W2K Server. Both are hooked up to another LAN, and lose network connections. At times one cannot even ping the DNS addresses. I activated Netwok Monitor on one of the clients and noticed a lot of network traffic. Disconnected the router from the switch and the local network came back on line. This particular client is using a Cisco 1600 router. Would a firewall help prevent unwanted traffic from coming in and leaving the LAN?