Hello, I have a rather complicated need to use a gre tunnel and I am having difficulty getting it working. The tunnel is between my home server and Oracle VM. Below is a picture of the topology with config.
Pings between the home server and Oracle VM over the gre tunnel do not seem to be going through as evidenced by tcpdump. I do notice however that the firewall has the correct state table showing that address translation. I am certain that both machines’ firewalls are not dropping packets because iptables is not showing anything dropped. I am at a loss here so I welcome any ideas.
I believe OP has made some mistakes when pasting the text
[Diagram] Oracle VM: Linux External IP: 192.0.2.1 Internal IP: 172.16.0.2 | | GRE Tunnel v Home Server: Linux Internal IP: 172.16.0.2 | | v Firewall: FreeBSD Internal IP: 172.16.0.1 External IP: 192.0.2.2 [Text] Home Linux Server GRE config: $ sudo ip tunnel add gre0 mode gre remote 172.16.0.2 local 192.0.2.1 ttl 255 $ sudo ip link set gre0 up $ sudo ip addr add 10.100.10.1/24 dev gre0 Home Linux Server GRE config: $ sudo ip tunnel add gre0 mode gre remote 192.0.2.2 local 192.0.2.1 ttl 255 $ sudo ip link set gre0 up $ sudo ip addr add 10.100.10.1/24 dev gre0 Firewall: nat on igb1 inet from ! (igb1) to any -> (igb1:0) nat on igb0 inet proto gre from 172.16.0.2 to any -> (igb1:0) rdr pass on igb1 inet proto gre from 141.148.84.178 to (igb1) -> 172.16.0.2gre implies you want to run dynamic routing over the tunnel but no routing is configured? If you don’t need dynamic routing (why would you on a P2P tunnel?) but do want privacy then use IPsec or SSH instead?