gre tunnel setup

I'm trying to setup a grep tunnel between a Linode and a BuyVM VPS. I've been following this guide.

I've ran the following on the BuyVM.

echo 'net.ipv4.ip_forward=1' >> /etc/sysctl.conf
sysctl -p
iptunnel add gre1 mode gre local BUYVM_PROTECTED_IP remote LINODE_IP ttl 255
ip addr add 192.168.168.1/30 dev gre1
ip link set gre1 up

I've ran the following on the Linode.

iptunnel add gre1 mode gre local BUYVM_UNPROTECTED_IP remote BUYVM_PROTECTED_IP ttl 255
ip addr add 192.168.168.2/30 dev gre1
ip link set gre1 up

So you can see I've tried to configure that the protected IP at BuyVM is tunnelled over the non-protected IP to Linode. Should this work? Currently I am unable to ping each other via the tunnel.

http://ift.tt/1dvHQ0Z