I've never seen such thing before.
In ubuntu 18.04 LTS almost after 6 months, I have problem in loading HTTP urls in Firefox, Chrome even by wget. But I have no problem with same urls in HTTPS mode. Ping also works for the same urls.
However this problem not seen in other devices connected to same network!
Any help appreciated...
Update I have a solution for this that's not intresting (actually headache):
In firefox from
Preferences > privacy > View Certificates > Delete All Server Certificates.Reboot the Ubuntu 18.04
- For limited time everything working fine, but after visiting one of my websites with SSL (https), all urls with http stop working!
I think this problem related to websites with self-signed certificates, however these websites doesn't have similar problems in other devices.
Hope somebody knows the reason...
Updated: Today I faced with another strange issue.
I've setup Wifi hotspot using my Android mobile with 4G data network & my laptop conncted to mentioned hotspot.
Everything worked fine, but changing hotspot to USB tethering caused http stopped working.
By switching back to hotspot the problem gone!
Had similar issue. There was URL filtering (parental control) enabled on the wifi router with some blocked URL's on port 80. Strange behavior, no matter what URL I add in the router for port 80, It would block all http traffic to ubuntu on cloud. It would also block http traffic when I had no rules but still have url filtering enabled.
When I add a url with https/tcp443 alone (without any port 80 blocked) then http traffic works or it also works with url filtering completely disabled...stupid.