In my lab assignment, I have to create a router. One of my networks is 192.168.10.0/24 while other is internet from a private network. I can ping both the router interfaces your ever I can't connect to internet. I have router as my Def gateway, enabled forwarding, allowed masquerade (on router) as iptables -t nat -A POSTROUTING -s 192.168.10.0/24 -o eth0. All my current firewalls are flushed and I'm using CentOS 6.9 without GUI.