YOE: 2.5 years
Status: CS Grad Student - Final year
Position: Software Engineer - Master's (Full Time) - United States
Location: United States (Not for any specific location)
Date: 09/18/2019
Result: Rejected

I just had 1 technical face-to-face interview. Since there were not many interview experiences for Cisco, I thought I'll share my experience anyways.

Face-to-face interview [1 Hour]:

1. Walked through my resume
2. Explain your favorite project that you did at your work?
3. How good are you in Computer Networks? I said that I was confident with Layer 4 and above. Apparently, the interviewer's BU focuses on Layer 2 and Layer 3 (Definitely not an excuse!)
4. What happens when you connect your laptop to a wifi network? Explain the steps
   a) Explain DHCP steps
   b) Draw message format and explain what the source and destination address would be in each step?
   c) Why does DHCP have 4 steps? why not just 2?
   d) Explain DNS and walk through the steps
5. Explain how computers that are on 2 different networks communicate with each other
   a) Explain ARP protocol and its steps
   b) Explain NAT, PAT
   c) Explain MAC address table
6. Explain spanning tree protocol and its purpose
7. What is the broadcast address of 20.20.20.10/29?
8. Paper Coding:
   Find the first non-repeating character in a string (https://leetcode.com/problems/first-unique-character-in-a-string/) preferably in C.
   Followup questions:
   a) How do you determine if there is a CPU/memory spike in a Linux machine where you have deployed this code?
   b) Write test cases for this code
   c) Maximum size of your data structure?

My takeaway:
Overall, it was a great interview experience.
I spent a lot of time on leetcode and somehow forgot to spend time on CS fundamentals [Networks and OS]. The coding part went well but made many fundamental mistakes in the networks section.

All the best for people applying!