I’m running 2003 SBS network with one main domain controller/exchange server and 10 desktops. We have firewall provided by our ISP and that’s acting as a DHCP server. However, network computers had problems connecting to a domain, so we’ve added dns record manually to each desktop. I’ve noticed that the main server keeps losing internet connection every now and then and all the computers with manual dns record as well. However, we have tried to work this problem around by manually adding the gateway as well, but the problem persisted.
If you take those records and leave the computers with dhcp settings internet will work,but eventually outlook will fail due to not being able to retrieve files from exchange and it’ll take long long time to load users profile when trying to login.