SIMULATION - Please open the ip_forward, and take effect permanently. 

See explanation below.

vim /etc/sysctl.conf net.ipv4.ip_forward = 1 sysctl ""w(takes effect immediately) If no "sysctl.conf" option, use these commands: sysctl ""a |grep net.ipv4 sysctl ""P net.ipv4.ip_forward = 1 sysctl -w