1. Have you got the core setup with 2 NICs, one connected to your external network and broadband router and the other connected to your internal network and the MD?
2. Is the internal network 192.168.80.0, and the internal interface has an IP address of 192.168.80.1?
3. The internal and external networks are not bridged in any way?
4. There is no DHCP server on the internal network except the core - this is the most important bit! (including no Windows PCs using Internet Connection Sharing)
5. The core is connected to the MD either with a direct ethernet cable or through a switch/hub (not a router)
1 : yes, I have 2 Nics connected as stated
2 : yes, and I have several other PC's who's all receives their IP from the core (dhcp server) by ex 192.168.80.253 (252, ..) I also have 2 PC's with fix IP 192.168.80.200 and 201
3 : I don't think so, it is a standard CD setup. How can I check that ?
4 : I have one windows PC in the network, but I don't use internet connection sharing, but may be there is a service running for that ? Do you know what I have to check to be sure that it is not running ?
5 : yes, in fact there are 2 switches
many thanks for your help