Cisco Software Engineer interview questions

They contacted me from Monster and setup the interview via email. Once they call, they asked me many technical java questions that I easily answered. They asked me about messaging, classes, recursion, data structures, sql, transactions, hash maps, interfaces, then they sent me an exercise that I had to answer within one hour. The exercises where rather simple, and they asked to write real compilable code

Data strcutures, C and OS is the thing that rules for a cisco interview...if you know them you can get through... first round : C second round : OS third round DS