This is just plain weird, it use to have access to internet and now it doesn't.
It can ping the local network and I could ssh into it, even through internet using it's public IP.
Here's the /etc/network/interface:
If I try to ping let's say google.com, it could resolve the IP address but that's about it.
iface lo inet loopback
iface eth4 inet manual
iface br0 inet static
iface eth2 inet static
Before it gave me the postfix error when I restarted networking service, but I just remove postfix since I don't need to send emails from it.
Could anyone enlightened me.