Dropbox, FileZilla = OK; Firefox, Safari can't get to web

[sunandsurf]

I've got a very frustrating situation and I hope there will be someone who will be able to figure this out.

My Oceanic modem is working fine. My wireless router is working fine. I can surf the web using my wireless router with my iPad.

With my iMac, I can connect to the web using FileZilla (to transfer files) and I can add files to my Dropbox account and I can update my Kaspersky Internet Security app BUT I can't get to the web using Firefox or Safari or iTunes!

Those apps will launch but will fail to load.

When I start up my iMac, I don't get the usual request to allow certain apps to access the web.

Clearly, it seems to me anyway, that the problem is somewhere in my iMac.

When I go to Preferences > Network and click diagnostics, it says my Ethernet AND wireless connections are working properly.

I'm at a loss as to what is preventing my web browsers and iTunes from accessing the web.

Everything was working fine until about a week ago and I don't recall installing any new apps.

Any suggestions would be very much appreciated. Thank you.

 

[Darth.Titan]

You need to check your Firewall settings under security in system prefs.

Or if Kaspersky has its own firewall, the problem is probably there.

Third party "security" software usually causes more problems than it solves in OS X.

 

[sunandsurf]

Thank you for your suggestions but I have my firewall off and my Kaspersky is just an anti-virus program, not a firewall.

I appreciate the suggestions, though.

 

[sunandsurf]

Found an answer here

I searched high and low and I believe I found ONE possible answer. I say "one" because while searching, I found that other people had faced a similar situation but their solution differed.

This is what I found works for me.

Someone wrote: "Motivated by the regulatory of this problem (about once a fortnight), I managed to find a fix for it. I found force quitting mDNSResponder in activity monitor, and letting the daemon restart automatically fixes the problem. I can only conclude that there's some kind of issue with the mDNSResponder daemon that causes it to either stop responding to DNS request, or fails to lookup DNS records."

You can read the entire thread here:
https://discussions.apple.com/thread/3017510

and note that this was written in 2011!

Anyway, I wasted a lot of hours hunting for this answer. I hope it will save someone else from wasting so much time when there are so many other more important things to do with their lives!

***. Less than an hour after posting the above, the problem came back. I force quit the mDNSResponder again but this time, it made no difference. I'm sending this message with my iPad which is connected to the web via my wireless router. Sigh.... What a waste of time....