Firefox 4 and Comodo Outbound Connections

Hey guys. Just noticed that when browsing in firefox my outbound connections in comodo can jump from something very small like 4 or 6 to something between 80 and (sometimes) even 300 connections with 89-96 percent labeled firefox.exe. This may have been going on for a while this is just the first time I’ve noticed it. Just wondering if that’s a known issue or if I may be at risk.

Using Firefox 4.0.1 and CIS 5.4.189822.1355

After a while of being idle, it goes back down. Only seems to happen while actually browsing. Thanks in advance for any help you are willing to provide.

By default, firefox along with most modern browsers, employs prefetching. There are two configuration options found in about:config that affect this:


Essentially, when you visit a web site the browser will attempt to identify any and all links on a page and pre-load, ether the DNS or the link. Hence the connections you see. The idea is to improve browser responsiveness.

If you don’t want this feature set:

network.dns.disablePrefetch = True
network.dns.disablePrefetch = False

I’m confused. The two options you listed are the same exact text yet you said to set one to true and the other to false. Was that a typo or am I missing something?

Also, it seems from what you said that this is normal behavior. If that’s the case, I might not even want to disable the prefetching feature as it does not seem to be causing me any issues. I was just worried that there might be something malicious taking place. If it is indeed normal, then I’m happy to not f**k with it :slight_smile:

Please let me know about the configuration setting though just in case I decide to be adventurous.

Apologies, I must have been on something when I posted that :a0 It should have been:

network.dns.disablePrefetch = True
network.prefetch-next = False

That’s for disabling prefetech, otherwise just leave be.

Some people don’t like prefetching, as they perceive a security in allowing this. There’s lots of info out there but here’s a couple of links:

DNS Prefetching and Its Privacy Implications: (PDF)
Old Nabble - IETF - Discuss - DNS prefetching

Awesome. Thanks again…you’re always very helpful :slight_smile: