[SOLVED] After upgrade to Gigabit internet, I can only connect to Google and Facebook

[SpecialEd]

We upgraded our cable internet to gigabit speed. It went fairly smoothly except for my Thinkpad T440. It can connect to the various networks but not to the Internet, except for Google pages and Facebook. Thunderbird and discord fail to connect too. Of the six PCs/laptops in our household all connect fine except for the T440 (by the way my wife uses two Thinkpads for work and they are both fine.) I booted a live version of Kubuntu 18.04 and it still would not connect.

Operating System: KDE neon 5.15

KDE Plasma Version: 5.15.3
KDE Frameworks Version: 5.56.0
Qt Version: 5.12.0
Kernel Version: 4.15.0-46-generic
OS Type: 64-bit
Processors: 4 × Intel® Core™ i7-4600U CPU @ 2.10GHz
Memory: 11.4 GiB of RAM

Network:   Card-1: Intel Ethernet Connection I218-LM driver: e1000e 
         IF: enp0s25 state: down mac: 28:d2:44:9a:b0:aa 
         Card-2: Intel Wireless 7260 driver: iwlwifi 
         IF: wlp3s0 state: up mac: e8:2a:ea:78:43:85

Any suggestions?

[Iangh]

Have you tried unplugging modem and router and then plugging them back in in that order. Make a new connection for the Thinkpad and see what happens. Also check IPv4 is automatic in network connection.

[SpecialEd]

Have you tried unplugging modem and router and then plugging them back in in that order. Make a new connection for the Thinkpad and see what happens. Also check IPv4 is automatic in network connection.

IPv4 is checked. The combo modem/router has been reset. My cable company sees the laptop and recognizes it. I can connect to Facebook and Google but nothing else. My email isn't connecting either. The other 6 systems and various tvs and tablets all connect without issue.

[Iangh]

It's got to be the PC as everything else is working. Have you tried flushing the dns? Another step I would take in Windows would be to delete the n/w adapter driver and then reinstall. Try the Ubuntu equivalent. Other than that I'm out. Hopefully an expert will pop along.

[SpecialEd]

I finally figured it out, due to idiots(me) messing with current setup. I have cable internet coming into the house at one end and run an ethernet cable from the router at one end to another router at the opposite end of the house for decent reception in the bedrooms. When we upgraded the new service, we -- for some reason-- changed the router setting in the back of our house to ROUTER instead of Access Point. Changing it back (just a trial and error sort of thing) fixed all the problems and we are back to cyber bliss with now gigabit speeds.

P.S. Thank you langh for taking a stab at it.

[Iangh]

I'm glad you figured it out.