I bought a router, set it up, a couple of sites do not work. How to fix?

Question

Computer networks

The bottom line is:
The other day I bought a dlink dir - 320 router. I set it up according to the book.
Now the sites don't open. Not all, but some. First Vkontakte and @mail.ru. but with them somehow the problem went away.
now https://bitcoin.org/ru/.
Error ERR_CONNECTION_TIMED_OUT
How can I fix this?

Answer 1

Check the mtu/mru setting

Answer 2

If you connect directly without a router, the same problems?
Clear the cache in the browser, check the file C:\Windows\System32\drivers\etc\hosts, open it with notepad, google what should be written there by default and delete the excess, if any