Hi, Reading this post Mac Virus/Malware Info I was concerned to learn for the first time about vulnerability in the DNS protocol (see the section entitled 'Why am I being redirected to other sites?'). The link mentions that this problem is either in your Mac or in your router and goes on to provide details about fixing it in Mac OS X. I've read and re-read these instructions and read and re-read the various links and I understand all the steps, what I would need to do etc and, to a certain extent, why. However, what I want to clarify is where I should implement these changes, on my Mac or on my router? The DNS server currently listed in my Mac's Network Preferences points to the IP address of my LAN, where my router is acting as the DHCP server for my home network. My router however, is current set-up to get my DNS address from my ISP automatically. I can over-ride this of course, as I can also make the suggested changes to my Mac. But which should I do? One or both? My guess is that if I change the DNS on my router then anyone attached to my network would get the benefit of those changes. But, if I were to connect to another network, my Mac would still default to whatever DNS was served by the router it is attached to. Alternatively, if I change the DNS settings on my Mac, no matter where I'm attached, it will always use those settings for DNS. However, if I change the settings on both my Mac and my router, will it have any adverse effects? Basic question (for those short on time ): Do I make DNS changes on my router, my Mac, or both? Thanks for reading!