I am trying to forward packets from HostA to HostB using ip-in-ip tunneling. While packets are reaching their destination, they are not being decapsulated by the receiving host, and thus being dropped thereafter. I feel as though I've exhausted all of google. In essense, it looks like the receiving host never sends the packets to the tunnel device for decapsulation.
The tutorial I've used most when trying this is here, but I have tried multiple methods and different tutorials, and am continuously met with the same problem. What am I missing?
ip tunnel add tun0 mode ipip local $hostA remote $hostB ip link set tun0 up ip addr add 10.10.10.1/24 dev tun0
ip tunnel add tun0 mode ipip local $hostB remote $hostA ip link set tun0 up ip addr add 10.10.10.2/24 dev tun0
Now, when I
ping 10.10.10.2, I get no response. HostB is showing (via
tcpdump -c 10 -nn src host 10.10.10.1 or src host $hostA):
(edited to remove actual ip address of hosts)
18:18:56.026192 IP [HostA eth0 IP] > [HostB eth0 IP]: IP 10.10.10.1 > 10.10.10.2: ICMP echo request, id 41073, seq 69, length 64 (ipip-proto-4)
The incoming packets look like they should, but they are never being decapsulated.
tcpdump -nni tun0 has no output, and no response is ever made to the ping.