Hello Neeraj
It’s great to see you’re preparing for the interview. It’s a great opportunity and I wish you success. Concerning the interview questions, from what I understand in your post, you will be able to ask clarification questions, correct? If so, here’s how I would approach these questions. A lot of the below is me just thinking aloud.:
Example 1: Design a network for 100 hosts.
Firstly, you need to clarify the nature of the hosts - are they servers, workstations, IoT devices, etc.? Also, clarify what kind of traffic will be served by the network - time-sensitive traffic like VoIP and video and/or mission-critical services, file sharing, databases, or simple Internet surfing. These factors will influence the network design greatly because they will affect bandwidth requirements, QoS, security considerations, and the topology.
- Network Topology: A typical design for 100 hosts could be based on a hierarchical network model with a core layer, distribution layer, and access layer. This design provides scalability, redundancy, and manageability.
- IP Addressing: You could use a single subnet (e.g., 192.168.1.0/24) for 100 hosts. This will allow for 254 hosts, which leaves room for growth. However, you may want to subnet into smaller subnets based on some other categorization of hosts (i.e. services, departments, type of devices, security, etc…)
- Redundancy: You could use protocols like HSRP/VRRP for gateway redundancy, and implement redundant links between switches to avoid single points of failure.
- Security: If you have multiple subnets, implement VLANs to segment the network and reduce broadcast traffic. Also, consider firewalls, intrusion prevention systems, and access control lists for enhanced security.
Follow up: Upgrade to 1000 hosts.
This follow-up question seems to be for evaluating the scalability built into the original design. You will need to consider
- your addressing scheme,
- bandwidth requirements,
- expansion of the access layer of the network while ensuring the distribution and core have enough bandwidth to handle the traffic
Monitoring: Network monitoring can be done using SNMP-based tools like SolarWinds, PRTG, etc. You can monitor network performance, and device status, and receive alerts for any anomalies. This will of course depend upon answers to some of the initial questions like what kind of hosts and what kind of traffic you can expect.
Example 2: Build an automated network design framework.
This is a broad question, and you might need to clarify what exactly they mean by an “automated network design framework”. If they’re talking about automating network configuration and management, then you could discuss technologies like:
- Software-defined networking (SDN): This allows for centralized network management and configuration.
- Network function virtualization (NFV): This can help to automate the deployment of network services.
- Configuration management tools like Ansible, Puppet, Chef, etc. These tools can automate the deployment and configuration of network devices.
- Intent-based networking (IBN): This is a form of network automation that uses machine learning and AI to automatically configure and manage networks.
Remember, the key to these design questions is to clarify the requirements first, and then propose a solution based on best practices and your own experience.
Out of the whole process, I as an interviewer, would evaluate what clarification questions were asked by the interviewee, rather than the final network design. The questions indicate the level of critical thinking involved in the process.
If you have further clarification questions, feel free to respond so that we can continue the conversation…
I hope this has been helpful!
Laz