Pardon my lack of security savvy- I dont know all the terminology. I've taken the comment below and updated. I get nightly DOS (browser) - this means I see the following attached picture on any browser - server not found or DNS not found. this usually lasts for hours. This happens for all browsers I use and all 3 pcs. I do get port scans also but i'm not as concerned about those, except they do happen very frequently for a non-wifi network. I hope this is clear enough re the symptoms. Here is a photo of what happens
i have completely bypassed wifi and even the router- I'm connecting straight to NBN cable (australian broadband fibre) so don't have wifi security issues. I have done some hardening of the pc but notice that ipv6 keeps reappearing after I remove it. However, even when ipv6 is off, there is disconnection.
Background: I have hardened my PC as much as I can ie removed unnecessary services such as fax and have bitdefender installed, but it doesn't report on the issue (and sorry to say their helpdesk customer service isn't the greatest so no help there).
What is the logical next step in troubleshooting this? I've spent many many days and weeks training my meager security knowledge up to deal with this. I feel I've reached as far as I can go on my own. I even have contacted a security expert to help but his services (2000 and no guarantee of success) are way beyond my budget, especially this time of year!
One of the commenters pointed out that I'm not likely important enough to be attacked and dismissed it as a non-attack. Ok, well, all I can say is that on a daily and nightly basis, I have no access to any pc for long periods of time (on all 3 of them) intermittently, though the problem starts usually after 730pm. I also more likely to get disconnected in evenings if I'm going to security related sites. I am not a celebrity or anyone important, but the fact is this is happening to me every day. I don't know why.
I only recently removed my router. It doesn't matter if I have a router or not, or if I have antivirus or not. The same thing happens.
Help would be appreciated