Network issues after upgrade

Hello,

I had previously been running ESET Smart Security without any problems. However, a few days ago I upgraded from Vista Home Premium to Vista Ultimate. Since then, the ESET firewall has not been working properly. As soon as the computer starts (or within 1 minute), I lose all internet connectivity. I can see that I am still connected to the local network, have my normal IP address, etc. Just no internet. Disabling the firewall instantly restores all functionality. Likewise, turning it on again brings the same behavior as above. Uninstalling and reinstalling ESET had no effect. Putting the firewall into either automatic or interactive mode does not help. (Interactive mode will prompt for approval of new items, but they remain blocked.) Resetting ESET to the default settings has no effect.

I am at a loss as to what may be causing the problem. Any help is appreciated.

Thanks,
Ben

 

Hello ben33333,

Make sure that the Windows Firewall is disabled. If it is and the issue persists, please contact our Customer Care Engineers here.

Thank you,
Richard

 

Windows Firewall is disabled. I checked the ESET logs and found hundreds of entries for "ARP Poisoning detected." I disabled that check so my connection works, but I have not idea what was causing it. There are a number of other computers using ESET on the same network, and none of them have this problem.