I've always use vnstat to measure traffic on any of my server but recently I have problem with Amazon EC2 bandwidth usage. I only have 1 interface(eth0) so I'm pretty sure I didn't miss anything. vnstat reported that I use ~30GB/month but Amazon billed me for ~160GB of bandwidth for EC2. I create new ticket with them and here's their reply.
Am I using the wrong tool(vnstat) here or is there something wrong on Amazon side? What do you think?