At first , try to change you local OS MTU size
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open cmd.exe
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enter:
ipconfig
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use your mouse rigth click to select and copy to clipboard your network interface name. Usually it is “Local Area Connection” for cable and “Wireless Network Connection” for wi-fi. Its possible that you have more then one. Choose the correct - the one you use for internet access. If in doubt, change every interface you see :). Dont worry, the change is reversable.:

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use the netsh commands to set MTU from default 1500 to 1400. Use mice right click to paste your clipboard just in right place. Note the quotation marks around its name. For the found name Local Area Connection (its possible different in your case):
netsh interface ipv4 set subinterface “Local Area Connection” mtu=1400 store=active
to check with current value, use the ‘show’ key:
netsh interface ipv4 show subinterface "Local Area Connection"
- try to connect the game. On fail, try set MTU to 1300, then 1200 … down to 600. But note: the lower MTU, the more laggy game will be.
On success, make the change persistent with store=persistent key:
netsh interface ipv4 set subinterface “Local Area Connection” mtu=1400 store=persistent
HINT: to calculate your maximum MTU value, use mtupath.exe and ADD 28 to its rightmost value of the “MSS IN RANGE”.
For the screenshot above it will be: 1432 + 28 = 1460