Interview Questions - Networking (Cisco/Juniper/Citrix , etc)

QoS Questions

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1. Shaper vs Policer

2. Usecase SrTCM vs TrTCM

3. Algorithmic explanation of SrTCM vs TrTCM

4. How WRED works ?

5. Color aware WRED and Precedence management ?

6. DWRR vs WRR ? 

7. How to load share among queues using Weights and different QoS Algorithms ?

8. Why do you need "trust COS" port-level configuration? is it going to prevent all the attacks ? 

ASIC and Network Questions:

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1. broadcom XGS pipeline

2. How L2 gets forwarded.

3. On Ethernet header what decides the next protocol ? If ethertype is used for something else too, what is it for ?

4. Can you draw a frame and it's fields and their significants for: Ethernet+double-tag VLAN + IPv4 header

Operating Systems:

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1. Mutex Vs Semaphore

2. IPC mechanisms : Signal Handling Basics, Socket Programming (NETLINK vs RAW SOCKET), 

3.Thread safe programming

4. Memory Layout of Process vs Thread. 

Design Questions:

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1. What Datastructure will you use for MAC table and IP routing table ? explain in detail about your decisions. 

2. How do you breakdown a problem: say for example if the current scenario of Covid-19 lockdown needs to be relaxed slowly over the weeks. how do you do it ? 

3. What is the difficult problem that you have faced recently and how did you solve it and talk about it .

C Programs:

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1. Endianness of the system

2. HTONS and NTOHS function

3. Height of a Binary tree

4. Reverse a linked list

Few Must DOs:

1. Watch this even if you know everything in basic Networking : https://www.youtube.com/playlist?list=PL8hvAJ8ypAInbY-qmtZ9RG0d7IpAkS7Dy

2. How does traceroute work https://networklessons.com/cisco/ccna-routing-switching-icnd1-100-105/traceroute