Amazon Cloud Support Engineer Database Administrative interview questions

I suppose to work as a SQL Database Administrator. It's was a 3 steps interview. The first was technical just about SQL Server, which I passed. The second was also technical but with other technologies questions, mainly network questions, such as DNS, TCP/IP, OSI, NETSTAT and because of this, I didn't succeed. I have a very poor knowledge about network. So, if you want to work at Amazon, study network questions, even if your job isn't something directly related with network.