It was set to true (enabled) and wondered if it was something I really needed or not. After doing a little bit of research, I began to have some serious doubts about it. Make no mistake, it does offer a slight advantage in terms of faster load times, but I'm not entirely convinced that the benefits outweigh the risks/disadvantages. So I disabled it, both in PM an Fx. In fact, according to the articles I've read, all the major browsers out there today have it enabled by default. Yes, that does includes Firefox, Opera, Chrome, IE v8 & v9. Decided for yourself whether you really want it or not. I've got a pretty fast connection here (10 Mbps) and disabling it did not hinder/slow down my browser at all.
Here's a page titled "What is DNS prefetching and why it should be enabled".
I disagree with the author's assertion that it should be, as it leads people to believe they're missing out on some great experience if it's not. After doing my own reading & research, I think it can be used or preferred by some users, but strongly disagree that it "should be" used.
I attended a seminar last year on DNS attacks & cache poisoning. (The seminar was geared for IT folks and network administrators) so the presented information would not have been "interesting" for most end users. However, I walked away with the understanding that of all the "theoretical" threats out there, it is perhaps one of the most likely (and severe threats) that can happen today.
Wiki page on Link prefetching
- Users and website operators who pay for the amount of bandwidth they use find themselves paying for traffic for pages the user might not actually visit, and advertisers might pay for viewed ads on sites that are never visited.
- Web statistics such as browser usage, search engine referers, and page hits may become less reliable due to registering page hits that were never seen by the user.
- Users may be exposed to more security risks - by downloading more pages, or from un-requested sites (additionally compounded as drive-by downloads become more advanced and diverse).
Another link for Reference:
- prefetching a web page in the background could eventually cause a user system to be infected by a malware (drive-by download attack), if this prefetched page contained a malicious code. In this given situation, the web browser of the victim would be compromised in a completely invisible way, since the user has not clicked on a particular link when the infection occurs. **
** preceding bullet points omitted for brevity sake. You can read the full text by click on the link above.
DNS Prefetching & Its Privacy Implications: When Good Things Go Bad
authors: Srinivas Krishnan & Fabian Monrose
PDF download here.
Edited by Tushman, 13 January 2012 - 03:48 PM.