Connect Another Net Using IP Tunnel

//computer one ip from ifconfig 192.168.1.2  public ip 2.2.2.2  
ip tunnel del ipip0
ip tunnel add ipip0 mode ipip remote 1.1.1.1 local 192.168.1.2
ip addr add 10.0.0.101/24 dev ipip0
ip link set ipip0 up

//computer two ip from ifconfig 192.168.100.2  public ip  1.1.1.1
ip tunnel del ipip0
ip tunnel add ipip0 mode ipip remote 2.2.2.2 local 192.168.100.2
ip addr add 10.0.0.102/24 dev ipip0
ip link set ipip0 up

//iptables

iptables -I INPUT -p 4 -j ACCEPT
iptables -I INPUT -p icmp -j ACCEPT
sysctl net.ipv4.ip_forward=1

//see network data

tcpdump -i eth0 |grep 2.2.2.2

//ping ip see available

ping 10.0.0.101