If you are taking the technical test or any of the online challenges, then you should prepare by reading this site as well as practicing and planning the online challenges in order to complete them in a fast time. The interviewers all have a standard batch of questions that they ask all applicants. Chances are good you will get the same "cookie-cutter" questions as the ones listed here and you will be able to ace the technical interviews. Most of the technical questions are purely academic and seemingly trivial in nature. Others involve things you would only see in problem edge-cases. Other questions are way too broad to express in detail in a limited time interview without any planning or reference material. If you're a decent system engineer who actually reads manuals, plans your configurations, and sets things up properly the first time so that you don't revisit low level problems constantly - you probably won't be able to answer them because you won't have dealt with the same problems on a constant basis in order to remember them. I assume the role must require you to rush to fix things in a short space of time that customers manage to repeatedly break horribly. I had mostly network questions for some reason even though I told them it wasn't my strong suit, despite wanting to improve in this field. - What is HTTP error 400 (Bad request) - Explain TCP congestion control and how it works (average round trip timer retries) - Explain everything in detail that happens when you type www.amazon.com into your browser (you will have to explain everything that happens in all the OSI layers, DHCP, DNS, routing protocols, HTTP ports and commands, TCP, load balancing, reverse proxies, CSS, databases, etc) - An FTP download starts slow and then speeds up towards the end. Why is that? - If you were to set up amazon.com from scratch, what would you do? (essentially describe everything involved in filling a datacentre with networking, hardware, software, storage, and getting it seen on the internet) - What does a router do if the MTU is too small for the packet (packet fragmentation, but you can talk about MSS and PMTUD) - What kind of DNS record that tells the name server to find it's own domain by looking at it's own records to avoid a recursive loop? (A DNS glue record) - Describe the Phases of IPSEC (IKE phase 1 - establish security association policies and Diffie helman key exchange, IKE phase 2 - establish the security association and regularly retest it) - How can a filesystem say it has free space but you are unable to write anything into it (out of inodes) - What happens when a router receives a packet? (describe routing, forwarding, and encapsulation processes) - What are the differences between OSPF and BGP? (OSPF is link-state used internally in sites, BGP is path vector - and connects sites via AS numbers to the public internet)
