We have a SBS 2003 server running with a standard dual network configuration. One card for accessing the internet and the other card to connect the server to the local network.
We frequently lose our internet connection for an unknown reason (although the other card is fine and all client computers are still able to access the server -- they just loose internet access.)
We also receive the 'Clearing the ARP Cache' error message when trying to repair the connection.
However, instead of rebooting the server, we simply go into the Network Connections, locate the card that is for the internet connection, right-click and choose 'Disable', and then after it is disabled, right-click and choose 'Enable'.
This seems to fix the problem until the next time it goes out.
It happens so frequently that I actually have a batch file that I modified in VBS and scheduled to run as a scheduled task once every minute of every day.
The batch file checks to see if it can ping the Google website (since that site is rarely down). If it can, then nothing happens. If it can't, I assume the internet connection is locked up and the batch file automatically disables and re-enables the network card to restore internet access. The batch file then also writes an entry to a text file recording the date and time that the connection had to be reset. That way, you have a quick record of all the times it went down. Let me know if you are interested and I can post the script file.
I know this isn't the ideal solution, but at least whenever the connection goes down, the system detects it and repairs it automatically within a two minute period.
