I'm using tcpdump to see if gre protocol is forwarding properly from my Debian linux box.
Here is the command I'm using
tcpdump -i eth0 proto 47 > /root/dump.txt
But the log file is empty I'm thinking because the protocol isn't even coming in, right?
When I look for protocol 6 (tcp) it fills up as I try and pptp in. Any ideas? Should I be seeing the gre protocol coming in?