The server (Windows XP Pro SP3) has two LAN cards (LAN card A and B) and is connected to the internet using ADSL. The ADSL connection is shared to LAN card B using Internet Connection Sharing.

The client (Windows XP Pro SP3) has one LAN card, and is connected to LAN card B of the server so that it has access to the internet.

The IP address on the LAN cards are defined as follows:

Server:
 LAN card A: 192.168.0.3/24 (manually defined by me)
 LAN card B: 192.168.0.1/24 (manually defined by Internet Connection Sharing)

Client:
 LAN card: 192.168.0.123/24 (assigned by DHCP) Default gateway: 192.168.0.1

From the server, I can ping 192.168.0.123 successfully.

From the client, it can access the internet without any problem. I can also ping 192.168.0.1 successfully but for 192.168.0.3, it failed with the Request Timeout error message.

Why did the ping fail, and what should be done to make the ping possible? (all firewalls have been turned off.)