Network engineer

What does a network engineer do?

A network engineer builds, secures and maintains the networks that connect an organisation's offices, data centres, cloud services and staff.

In Singapore, you will find the role in banks, telcos, hospitals, government agencies, managed service providers and any firm with several sites.

The job sits in the IT infrastructure team, usually under an infrastructure or network manager. An associate engineer handles monitoring, configuration and first-line fixes. A more experienced engineer owns changes, upgrades and incident resolution.

You work with security analysts, cloud engineers, the service desk, application teams and outside vendors such as internet providers and equipment suppliers. Clear documentation matters as much as configuration skill.

What the work involves

• Monitor network health and respond to alerts on links, switches, routers and firewalls.
• Configure switches, routers, VLANs, firewall rules and VPN tunnels under approved change requests.
• Diagnose faults, rank incidents by impact, and record the cause and the fix.
• Apply patches and firmware upgrades during agreed maintenance windows.
• Update network diagrams, asset lists and procedures after every change.
• Check bandwidth use and plan for capacity, load balancing and backup links.

Pay in Singapore

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Skills a network engineer needs

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Network engineer job description

We are looking for a network engineer to run and improve our office, data centre and cloud networks in Singapore.

You will configure and monitor network equipment, keep it secure, fix incidents quickly and document your work. You will join the infrastructure team and work with security, cloud and support colleagues. Hands-on troubleshooting experience and CCNA-level knowledge are typically expected.

Responsibilities

• Install, configure and maintain switches, routers, wireless controllers and firewalls.
• Set up and support site-to-site and remote-access VPNs.
• Monitor the network for faults, congestion and signs of a security breach.
• Troubleshoot and resolve incidents, and escalate to vendors when needed.
• Apply patches, firmware upgrades and configuration backups on schedule.
• Review bandwidth use and recommend changes to capacity, redundancy and load balancing.
• Keep network diagrams, IP address plans and incident records up to date.
• Prepare technical specifications for equipment purchases and work with vendors on quotes and support.
• Help write and test disaster recovery plans for network services.
• Connect on-premises networks to cloud environments such as AWS, Azure or Google Cloud.

Requirements

• Diploma or degree in IT, computer engineering, electronics or a related field. Some employers accept experience instead.
• Typically 0 to 2 years of experience for associate roles and 2 to 5 years for engineer roles.
• CCNA or equivalent knowledge of routing, switching, VLANs and IP addressing.
• Hands-on experience with firewalls and VPNs on at least one major platform.
• Working Linux command-line skills, plus basic knowledge of cloud networking.
• Willingness to join on-call rotations and after-hours maintenance windows.

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Network engineer career path

Network engineers in Singapore typically start as associates, move into engineer roles, then specialise or take on leadership.

The first two steps follow the SkillsFuture ladder, and the later steps are common job titles.

1. Associate network engineer

   Entry · SkillsFuture title

   You support deployment and daily operations. You monitor links, assist with installation and testing, handle first-line incidents and keep documentation current.

2. Network engineer

   Mid · SkillsFuture title

   You configure and secure network components on your own, resolve incidents, plan upgrades and capacity, and work with vendors on equipment and support.

3. Senior network engineer

   Senior

   You design changes for multiple sites, handle the hardest incidents, guide junior staff and review the security and resilience of the network.

4. Network architect or team lead

   Lead

   You set network designs and standards, plan major projects such as data centre or cloud moves, and lead a small team.

5. Network or infrastructure manager

   Head

   You are responsible for stable, secure network and communications services. You manage budgets, vendors, service levels and the team, and present options to business stakeholders.

Steps marked "SkillsFuture title" follow the career pathway in the SkillsFuture Skills Framework. The others are titles commonly used in Singapore.

Related jobs and their pay

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Network engineer interview questions

We wrote these questions from the skills this job needs. They are not an official question bank.

1. Walk me through what happens on the network when a user types a web address into a browser.

   What a good answer covers

   • DNS lookup to resolve the name to an IP address
   • ARP and the default gateway for traffic leaving the subnet
   • Routing hops to the destination
   • TCP three-way handshake, then TLS negotiation
   • Where firewalls, NAT or proxies sit in the path

2. What is the difference between a switch, a router and a Layer 3 switch, and when would you use VLANs?

   What a good answer covers

   • Switches forward frames by MAC address within a network
   • Routers forward packets between networks by IP address
   • Layer 3 switches route between VLANs at high speed inside a site
   • VLANs separate traffic for security and to limit broadcasts
   • Inter-VLAN routing and access control between segments

3. How does OSPF work, and when would you choose it over static routes?

   What a good answer covers

   • Link-state protocol where routers share topology and build a map
   • Neighbour adjacencies, areas and cost-based path choice
   • Faster recovery after a link failure than manual changes
   • Static routes suit small or stub networks with one path
   • Common checks: neighbour state, area and timer mismatches

4. What is Spanning Tree Protocol, and what can go wrong if it is misconfigured?

   What a good answer covers

   • Prevents Layer 2 loops by blocking redundant paths
   • Root bridge election and why you set it deliberately
   • Broadcast storms and MAC table instability when loops form
   • Protections such as PortFast and BPDU guard on access ports
   • How you would find the loop, for example by checking port flapping and CPU load

5. How would you set up a site-to-site IPsec VPN between the head office and a branch?

   What a good answer covers

   • Agree peer addresses, encryption and authentication settings on both sides
   • Define the traffic each side sends through the tunnel
   • The two negotiation phases and what each sets up
   • NAT traversal and overlapping address ranges
   • Testing the tunnel, then monitoring it and alerting on drops

6. You are placing a new web server in a DMZ. How do you design the firewall rules?

   What a good answer covers

   • Default deny, then allow only the ports the service needs
   • Separate rules for inbound internet traffic and for server-to-database traffic
   • Rule order, naming and comments so others can review them
   • Logging on denied and sensitive traffic
   • Regular review to remove unused rules

7. Which Linux commands do you use to troubleshoot a connectivity problem on a server?

   What a good answer covers

   • ip addr and ip route to check addresses and routes
   • ping and traceroute to test reachability and path
   • ss to see listening ports and connections
   • dig or nslookup for DNS problems
   • tcpdump to confirm whether packets arrive and leave

8. How would you connect an office network to a virtual network in AWS or Azure?

   What a good answer covers

   • Choose a VPN or a dedicated private link based on the need for speed and reliability
   • Plan non-overlapping address ranges first
   • Configure route tables and subnets on the cloud side
   • Security groups or network security rules compared with on-premises firewalls
   • Monitoring the connection and planning for failover

9. How do you use a tool like ChatGPT in your network work, and what would you never paste into it?

   What a good answer covers

   • Uses it to draft documentation, explain error messages or outline a plan
   • Checks every command and configuration in a lab before use
   • Never pastes passwords, keys, full configurations or customer data
   • Strips or replaces IP addresses and device names where possible
   • Follows the company's policy on approved tools

1. Staff in one office say a cloud application is slow, while other offices are fine. How do you investigate?

   What a good answer covers

   • Confirm the scope: who, which application, since when
   • Check link utilisation, errors and latency at that site
   • Compare DNS results and traceroute paths with a working office
   • Ask what changed recently, such as firewall rules or a routing change
   • Contact the internet provider if the fault is outside your network, and keep users updated

2. Monitoring shows a server sending large amounts of traffic to an unknown outside address at night. What do you do?

   What a good answer covers

   • Treat it as a possible breach and alert the security team at once
   • Contain it, for example by blocking the destination or isolating the server, as policy allows
   • Preserve logs and packet captures before changing anything
   • Identify what else the server talked to
   • Record a timeline for the incident report

3. You must upgrade firmware on the main pair of firewalls, and the business allows only a short outage. How do you plan it?

   What a good answer covers

   • Raise a change request with a clear window, impact and rollback plan
   • Back up configurations and confirm the version path from the vendor
   • Upgrade the standby unit first, fail over, then upgrade the other
   • Test key applications and VPNs straight after
   • Tell stakeholders before and after the change

1. Tell me about a time you fixed a network incident under pressure.

   What a good answer covers

   • Clear description of the impact and the deadline
   • How you narrowed down the cause step by step
   • How you communicated with users and your manager during the outage
   • The fix and the root cause
   • What you documented or changed to prevent a repeat

2. Describe a time you explained a technical problem to people who are not in IT.

   What a good answer covers

   • Chose simple words and avoided jargon
   • Focused on impact and next steps over technical detail
   • Checked that the listener understood
   • Followed up in writing
   • Result: decision made or expectation set

1. Your network logs record user IP addresses and browsing activity. How do you handle them under the Personal Data Protection Act (PDPA)?

   What a good answer covers

   • Logs tied to identifiable people can count as personal data
   • Collect and keep only what you need for security and operations
   • Restrict who can read the logs and protect them with access controls
   • Set a retention period and delete logs when no longer needed
   • Refer questions on purpose and consent to the organisation's data protection officer

2. You are placed with a bank client. What do you know about the Monetary Authority of Singapore (MAS) expectations for network security?

   What a good answer covers

   • MAS sets technology risk expectations for financial institutions
   • Typical themes: network segmentation, access control, logging and change management
   • Resilience and recovery matter, so redundancy and tested recovery plans are expected
   • You would follow the bank's own policies and audit requirements
   • Say honestly what you would need to read up on instead of guessing details

Common questions about a network engineer job

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