حل مشکل اتصال به بعضی از سایت ها در هنگام استفاده از اتصال PPTP

This worked for me when I had to switch based on the connection (specific vpn) and not just on the interface. Replace YourConnectionName with the name of your connection from /etc/NetworkManager/system-connections (the id field in the file, not the filename).

#!/bin/bash # if this is not the vpn connection, exit without error if [ "x$CONNECTION_ID" != xYourConnectionName ]; then exit 0 fi # if the interface is down (connection is being torn down) exit without error /sbin/ip a s $VPN_IP_IFACE || exit 0 # set mtu to low enough value to pass through vpn /sbin/ifconfig $VPN_IP_IFACE mtu 1300

برای من روی اتصال شبکه 

mtu ۱۵۰۰

روی اتصال pptp

mtu 1300