Can't connect to my domain/website!

[doogald]

* I have Kaspersky's security suite installed on the computer - but it's only activated for virus protection and even quitting this completely makes no difference.

As these utilities I believe install kernel extensions onto the Mac, I am wondering if there is something in Kaspersky that is blocking that IP address? Since your iOS device within the WiFi network can get to the site, that rules out something on the routers or blocking by your isp. And since I can get response to the site from Mojave, it’s not something specific to MacOS.

(If you are able to use a hotspot feature through your mobile carrier from your iPhone or an LTE iPad, that’s another way to isolate the system from your network - create a temporary hotspot to the phone or iPad and try the ping to see if it gets through. That would isolate seeing if it’s a network issue.) But, I don’t think that’s it. I also wouldn’t bother trying to connect the iMac through the isp router/modem at this point. That’s too much bother for what I think the issue may be.

I’d strongly suggest at least completely uninstalling Kaspersky and restart the Mac to see if that changes anything. You can always reinstall the suite if it makes no difference. It may not be Kaspersky, but those security suites do install a bunch of system stuff to try to protect you. I’m wondering if it’s over-protecting in this case.

 

[gregory_opera]

Okay, I think I have identified what the problem is... I just don't know why it is a problem.

Much to my surprise, if I use my iPhone XR as a "hotspot", I can connect to my domain without issue (I didn't try to setup CalDAV/CardDAV/etc - but presumably it too works just fine under this scenario), which means that something on our Wi-Fi network is blocking the macOS computers - and only the macOS computers - from accessing this particular domain (quite literally nothing else has issues when connected to the very same Wi-Fi network)(even our various iPhones can access this particular domain without issue).

I did not disable Kaspersky's security suite when I conducted this test (in other words, Kaspersky is seemingly not to blame).

Any ideas?

 

[doogald]

Try uninstalling Kaspersky (and any other security suite) and see if that fixes it. Worst case is you have to re-install.

No, do not just “disable it” - completely uninstall it (the Kaspersky .dmg install should have an uninstall routine inside it), restart the computer, see if that fixes it. You only have to test on one computer. Again, if you have any other security apps installed, get rid of those as well.

 

[gregory_opera]

Try uninstalling Kaspersky (and any other security suite) and see if that fixes it. Worst case is you have to re-install.

No change after (completely) removing and re-installing Kaspersky Internet Security, then restarting.

 

[doogald]

Ok, I'd say the next thing to try is to turn on WiFi temporarily on the cable router (if you can; if you can't, maybe try connecting by ethernet; hopefully that's not too much of a pain), connect to that router, and see if you get the same issue. If it is a router issue, that may be able to isolate whether it's the cable router or the Nighthawk.

 

[gregory_opera]

I connected to both modem/routers via ethernet and was able to access Apple.com just fine... No change to being able to access my website though (i.e. it was not accessible).

So somebody on another forum found the answer for me; it was a Network Address Translation (NAT) issue - I had this enabled on both modem/routers... Once I disabled NAT on the Netgear C6300BD-1TLAUS (i.e. the ISP-supplied one which provides my actual Internet connection), powered it off for thirty minutes and then powered it back on, the issue was fixed.

I'm not too sure why it was a problem all of a sudden now (my domain had always worked fine until recently), but it's fixed, so that's what's important.

Thanks for all the help everyone has given me here though... You guys may not have resolved the issue and the support may have trickled off towards the end - but I was pleasantly surprised at just how much help some of you quickly offered me, so I'm genuinely appreciative regardless.

 

[Noomok]

Where did you find the detailed answer? I also ran into this problem

 

[gregory_opera]

Here.