I think the R470T+ does not support GRE.

Try to upgrade to the latest firmware. If the problem still exists, you can contact the TP-link supporters for help.

Have the LED blinks or on? Close the Anti-Virus Software and firewall and try again. Have a good luck!

Which kind of VLAN do you appy? And if a port belongs to two VLAN in 802.1Q VLAN, the data from the port can go through both VLANs.

Maybe you can try to blcok UDP data from high speed WAN so that the UDP data can only go through low speed WAN.

hi Koperek, PPTP/L2TP/IPsec VPN are all Point-to-Point, that is say, when you set up a VPN between two side, the two side is connected directly, but it can not relay the data to other Point that is...