There is an Internet on Windows - there is no Internet on Linux ... Magic?

Question

linux

Hi all! Such a thing. Went to live in a new place. Moscow. Worth MGTS GPON.
And such a strange effect - on all tablets, smartphones and other things and on my laptop under win7 - there is an Internet without any problems.
But when I reboot into my native Debian 8, the network mysteriously disappears.
Moreover, the ping goes to any sites, the dns works, and the browser is empty. ssh doesn't work for me either.
I don't even know where to start digging. The problem is not in the laptop, because in other networks everything always worked.
And! Even in this network, the Internet sometimes appears. And then disappears again. I'm just at a loss.
Any ideas as to what exactly is going on?

Answer 1

It looks like a high MTU
Find the correct MTU with this command: You will need to change the number "1500" to lower values ​​until something like
and normal pings will start, then go to your network-manager and enter the value that you picked up
there, here are the values ​​\u200b\u200bthat you must sort through in turn, from top to bottom:

Values

1500 The biggest-sized IP packet that can normally traverse the Internet without getting fragmented. Typical MTU for non-PPPoE, non-VPN connections.
1492 The maximum MTU recommended for Internet PPPoE implementations.
1472 The maximum ping data payload before fragmentation errors are received on non-PPPoE, non-VPN connections.
1460 TCP Data size (MSS) when MTU is 1500 and not using PPPoE.
1464 The maximum ping data payload before fragmentation errors are received when using a PPPoE-connected machine.
1452 TCP Data size (MSS) when MTU is 1492 and using PPPoE.
576 Typically recommended as the MTU for dial-up type applications, leaving 536 bytes of TCP data.
48 The sum of IP, TCP and PPPoE headers.
40 The sum of IP and TCP headers.
28 The sum of IP and ICMP headers.

Answer 2

ip v6 - interface - raised on linux?