Don F contacted me about a problem he was having after following my how-to article “Share an internet connection with OS X:The Scenic Route” published in May 2004 issue of Australian Macworld.
Don had purchased an additional ethernet card for his Mac in order to share his broadband connection with other computers in his house. However while the other machines appeared to be being configured correctly they were unable to see the Internet
It turns out that he also had the personal Firewall enabled (in Sharing in System Preferences) and this was interfering with the sharing function. Disabling the firewall appears to allow sharing to work again.
Obviously switching off the firewall is not the best solution to Don’s problem but I don’t have an alternative for him at this time
I will continue to investigate this matter