Interview Guide: Network and Computer Systems Operators

In the growing field of technology, it can be difficult to find someone with the right set of skills and experience to meet the needs of the role you're trying to fill. Network and Computer Systems Operators perform a variety of tasks to establish and maintain multiple aspects of computer equipment, software, hardware and mainframe networks. The following list of questions is here as a guide to help in the hiring process.

Interview Questions

Common Questions

1. Are you familiar with the Microsoft, Linux or Apple platforms? Please elaborate on your experience. 
2. What is your favourite technology platform? (i.e., Microsoft, Linux, Apple).
3. How do you keep up-to-date with technological changes?
4. Do you think you have a sound understanding of networking principles and protocols? (OSI Network Layer Model, TCPIP, ATM, etc.)
5. Please explain the link between OSI and TCP/IP models
6. What were the most significant networking challenges in your past role? (e.g. outdated equipment, unrealistic demands of the equipment, overloaded equipment.)
7. Describe the most significant operational crisis you can recall and how it was resolved.
8. In a crisis situation, how did you assign responsibility for the incident resolution to the right support team(s) or individual(s), including third-party vendors? How did you coordinate/monitor the progress and resolution?
9. How do you ensure you are communicating properly with a team member, co-worker or external party? How would you rate your communication skills—both verbal and written?
10. How do you remotely coach someone who has little or no technical knowledge through solving a problem? Provide an example of how you handled yourself when an employee did not understand your directions.
11. In your experience, have you interacted more with end-users or members of the technology team? Which do you prefer?
12. In your current or past role(s), how much time did you spend at your desk, on the phone, on your feet or in meetings?
13. Are you able to multitask? Are you okay with consistently being interrupted or does this bother you? How do you provide efficient resolutions and solutions? How do you organize your work day?
14. What is your ideal technical position today and 5 years from now?

Systems Administrator

ROLES AND RESPONSIBILITIES

1. How large was your technology team and where did your role fit within it?
2. Did your role encompass all systems or did you specialize? (servers, network, support)
3. To what extent were you the point person to support employees with email, phone, printers, software installation and networking challenges?
4. In your past position what were your core responsibilities (e.g., build servers, manage back-ups, monitor servers for various types of failures, monitor email flow and website availability)?

SERVER OPERATING SYSTEMS AND BACKUPS

1. What is your experience building and configuring Windows servers? (2008/2008 R2/2012/2012R2/2016/2019)
2. What Linux server distributions have you worked with? (RHEL, CentOS, Ubuntu, Debian)
3. Do you have experience setting up Windows or Linux servers in a fault tolerant cluster?
4. Did you perform daily backup operations, ensuring all required file systems and systems data were successfully backed up to the appropriate media, and that the recovery tapes or discs were created? Was the media recycled and sent off-site as necessary? How did you perform backups? (incremental, full) 
5. What server backup systems do you have experience with? (Symantec BackupExec/NetBackup, EMC Networker, IBM TSM, CA Technologies ArcServe, HP Data Protector)
6. Describe an experience recovering a system from a critical failure. Please describe the type of failure and how you restored the system to high stability.

DESKTOP SOFTWARE

1. What desktop operating systems are you familiar with? (Windows 7/8.x/10, Mac OS, Linux– which distribution)
2. What desktop Anti-Virus applications do you have experience with? Please elaborate.
3. What desktop office suites are you familiar with? (Microsoft Office, Libre/Open Office, iWork)

VIRTUALIZATION

1. What is your experience managing virtualized environments and related infrastructure? (VMWare, VirtualBox, XEN, KVM, Microsoft Hyper V)
2. Did you manage a storage network for the virtualization environment (SAN)?
3. Describe the two types of virtualization.
4. A virtual DC server is down. What do you do?

USER ACCOUNTS AND EMAIL

1. Do you have experience with user security databases? (Microsoft Active Directory, Apple OpenDirectory, OpenLDAP)
2. Have you managed users and/or computers with Active Directory Group Policies?
3. Are you proficient in shell scripting? (bash, Perl, Powershell, VBScript)
4. Do you have experience with Microsoft Exchange, another email server or a Message Transfer Agent (MTA)? (Sendmail, Postfix, Exim)
5. Have you set up Microsoft Exchange in a fault tolerant cluster?

WEB, DATABASE AND CLOUD SERVERS

1. Have you administered a web server? (IIS, Apache, NGINX, Node)
2. Did the web servers serve simple static pages or did they run dynamic scripts and connect to external databases?
3. What web server scripting engines have you worked with? (Asp, Asp.Net, PHP, Perl, Node)
4. Do you have experience setting up web servers in a fault tolerant cluster? Do you have experience setting up database servers in a fault tolerant cluster?
5. Do you have experience with any transactional database servers? (Microsoft SQL-Server, Oracle, DB2, PostgreSQL)
6. Do you have hands-on experience supporting and administering hosted/cloud-based solutions? (Azure, AWS, Atlassian, Google Apps)

SECURITY

1. Do you have any experience setting up and using an Intrusion Detection System (IDS) such as SNORT?
2. Do you have any experience setting up Firewalls to protect an entire network? (Cisco, CheckPoint, SonicWall, pfSense, iPCop)
3. Do you have any experience setting up VPN servers? (PPTP, IPSEC, OpenVPN)
4. Do you have any experience hardening Windows and Linux servers?
5. Have you used any host security tools such as Tripwire?
6. Did you perform regular security monitoring to identify any possible intrusions? How did you respond to security alerts? Provide an example.

PROCESS AND REPORTING

1. How do you document your configuration, installing and troubleshooting?
2. Do you have Microsoft Visio experience?
3. Do you have experience with using an issue tracking system? (Bugzilla, RT, JIRA, Remedy, TFS)
4. Did you research, test and deploy new client and server software? Were you responsible for rolling out hardware and software? How did you prepare users for any downtime that may result from a roll-out?
5. Did you research and recommend innovative and where possible, automated, approaches for system administration tasks? Give an example.
6. Did you perform periodic performance reporting to support capacity planning?

MONITORING AND PERFORMANCE TUNING

1. Did you proactively monitor backend systems, applying patches and updates while resolving issues?
2. Do you have any experience using an automated system monitoring tool such as NAGIOS?
3. Do you configure, manage and monitor logs?
4. Did you perform ongoing performance tuning, hardware upgrades and resource optimization as required? (e.g. configure CPU, memory and disk partitions)

Network Engineer or Network Administrator

ROLES, RESPONSIBILITIES AND PROCESS

1. In your past position what were your core activities?
2. Tell me about a time you resolved a detailed technical network operational or network connectivity issue that had been escalated to the network team.
3. Are you comfortable with handling network-related change management to ensure all changes are under standard procedure and control?
4. How do you perform network asset management, including maintenance of network component inventory and related documentation and technical specification? What tools did you use to accomplish this goal, and what are your preferred tools?
5. How do you achieve on-site configuration, monitoring, and maintaining servers? What is your process and what software have you used?
6. When rolling out IT projects, have you followed a System Design Life Cycle? Please elaborate.
7. Have you participated in Performance Network Operational Audits?
8. Do you have any certifications? (Cisco, Network+, Juniper)

LANs

1. What is your experience setting up layer 2 technologies such as switches and hubs?
2. Have you ever set up an automatic failover layer 2 configuration using Spanning Tree?
3. Have you ever worked with the Simple Network Management Protocol? What monitoring software did you use? (SolarWinds, Spiceworks)
4. Do you have any experience diagnosing network problems with a packet capture tool such as WireShark?
5. Have you ever used advanced layer 2 switch capabilities such as port duplication or RMON to troubleshoot a network problem?
6. Do you have any experience setting up VLANs to segregate and prioritize traffic?
7. Do you have any experience with any Layer 2 Quality of Service (QOS) technologies and traffic shaping?
8. Have you ever set up and managed DHCP on a local LAN? Why do you use DHCP? 

WANs

1. What wide area link technologies have you worked with? (MPLS, ATM, FrameRelay)
2. Have you setup and managed DCHP over a WAN using relay agents? What is the command? (IP helper-address)
3. Have you setup DNS for an enterprise network? How did you ensure its availability for all WAN nodes?
4. What experience do you have setting up authentication systems (Active Directory, RADIUS) over the WAN? How did you ensure its availability for all WAN nodes?
5. Do you have any experience with IPAM technologies that integrate DHCP and DNS management? Please elaborate.
6. What tools have you used to monitor the availability of WAN links?

ROUTING

1. What internal dynamic routing protocols have you worked with? (RIP, OSPF, EIGRP)
2. Have you ever worked with BGP? Please elaborate.
3. Do you have any experience troubleshooting route convergence problems?
4. Do you have any Cisco IOS experience?
5. Have you ever worked with router based QOS and traffic shaping? Why do we use QOS?
6. What is an ACL? Which type for ipv6? (named extended)

WIRELESS NETWORKING

1. Do you have experience planning, implementing and troubleshooting a wireless mesh network?
2. Do you have experience with enterprise-level wireless access points and access point controllers?

VPNs

1. Have you set up and configured a VPN server? What VPN technology did it use? (PPTP, IPSEC, OpenVPN)
2. List the distinct types of VPN clients and the VPN technology that they used that you are familiar with. (Windows Workstation-PPTP, Apple iPad-Cisco IPSec, Linux Workstation– OpenVPN)

TELECOM

1. What telecom protocols/stacks have you worked with? (SS7, H.323, SIP)
2. Have you set up a VoIP telephone system? What vendor product line did you implement?
3. What major VoIP components have you worked with? (Signalling Gateway Controller, Media Gateway, Media Server, Application Server)
4. Do you have any experience with Asterisk?
5. What experience with classic PBX telephone systems do you have?
6. Do you have experience with Telecom Change Controls regarding Change Management?

FIREWALLS

1. What firewall products have you worked with? (Cisco, CheckPoint, SonicWall, pfSense, IPCop)
2. Have you ever set up an internet proxy server to improve internet access performance and/or control access to websites?
3. Have you ever worked with content filtering and/or firewall anti-virus components? Please elaborate.
4. Do you have any experience troubleshooting and resolving Network Address Translation (NAT) problems?
5. How can we use NAT with one address? (port address translation, overload)
6. Have you ever set up a firewall in a load balancing configuration to leverage multiple internet connections?
7. Have you ever set up multiple firewalls to provide a fault tolerant access to a website hosted in a Demilitarized Zone (DMZ)?

SECURITY

1. Do you have any experience with Intrusion Detection Systems (IDS) such as SNORT?
2. Have you performed network security audits? What tools did you use? What does CIA stand for in security?
3. Do you have any experience using open source security toolsets such as Kali Linux?
4. Do you have any experience with penetration testing frameworks such as Metasploit?