L3 Network Engineer

AMK Technology; Singapore; On-site; SGD 90,000 - 130,000; Full time

Job summary

Amk Technology in Singapore is seeking an experienced L3 Network Engineer to manage enterprise network infrastructure across vendors. You will be the escalation point for complex incidents and collaborate with L1/L2, infrastructure, cybersecurity teams and business stakeholders to ensure a highly available network.

The role covers routing and switching, firewall and security, SD-WAN, wireless, and network projects.

Qualifications

• 5–8+ years of enterprise network engineering experience.
• Strong L3 troubleshooting experience.
• Experience in multi-vendor environments.
• CCNP/JNCIP or equivalent preferred.
• ITIL knowledge and incident/change management.

Responsibilities

• Provide L3 technical support for complex network incidents escalated from L1/L2 teams.
• Troubleshoot complex issues across LAN, WAN, Internet, WLAN, VPN, routing, switching, and firewall environments.
• Perform detailed network analysis using logs, packet captures, routing tables and network monitoring tools.
• Lead troubleshooting for major incidents and provide technical support during critical outages.
• Perform root cause analysis (RCA) and identify permanent corrective actions.
• Provide technical guidance and mentoring to L1/L2 network engineers.

Skills

TCP/IP

DNS

DHCP

NAT

VLAN

OSPF

BGP

Troubleshooting

Packet Captures

Network Monitoring

Security Concepts

Mentoring

Education

Diploma or Degree in IT/CS/Networking

Tools

Cisco IOS

Fortinet FortiGate

Palo Alto

Juniper Junos

Meraki

UniFi

Job description

The L3 Network Engineer is responsible for providing advanced technical support, troubleshooting, implementation, and management of enterprise network infrastructure across multiple technologies and vendors. The role will serve as the Level 3 technical escalation point for complex network incidents and will work closely with L1/L2 engineers, infrastructure teams, cybersecurity teams, vendors, and business stakeholders to maintain a stable, secure, and highly available network environment.

Key Responsibilities

L3 Network Support & Troubleshooting

• Provide L3 technical support for complex network incidents escalated from L1/L2 teams.
• Troubleshoot complex issues across LAN, WAN, Internet, WLAN, VPN, routing, switching, and firewall environments.
• Perform detailed network analysis using logs, packet captures, routing tables and network monitoring tools.
• Lead troubleshooting for major incidents and provide technical support during critical outages.
• Perform root cause analysis (RCA) and identify permanent corrective actions.
• Provide technical guidance and mentoring to L1/L2 network engineers.

Network Infrastructure Management

• Cisco - Routers, switches, Catalyst, Nexus and related networking technologies.
• Fortinet - FortiGate firewalls, VPN, security policies and FortiManager/FortiAnalyzer where applicable.
• Palo Alto - Next-generation firewalls, security policies, VPN and related security technologies.
• Juniper - Routers, switches and enterprise networking platforms.
• UniFi - Wireless and LAN infrastructure.
• Cisco Meraki - Switches, wireless access points, security appliances and cloud-managed networking.

Routing & Switching

• Configure and troubleshoot BGP, OSPF, VLAN, STP, VRF, trunking, LACP/EtherChannel and inter-VLAN routing.
• Troubleshoot routing and connectivity issues across LAN, WAN and Internet environments.
• Analyse routing paths and network traffic to identify performance and connectivity issues.
• Support network redundancy, high availability and failover configurations.

Firewall & Network Security

• Configure, troubleshoot and maintain Fortinet and Palo Alto firewalls.
• Support firewall policies, NAT, VPN, routing and security profiles.
• Troubleshoot application connectivity and firewall-related issues.
• Work closely with cybersecurity teams on network security requirements.
• Review and implement firewall changes in accordance with approved change-management processes.

Wireless & SD-WAN

• Support enterprise wireless infrastructure across Cisco, Meraki, UniFi and other wireless platforms.
• Troubleshoot wireless connectivity, authentication, coverage and performance issues.
• Support SD-WAN and Internet connectivity where applicable.
• Monitor network performance and proactively identify potential issues.

Network Projects & Changes

• Participate in network migration, upgrade, refresh and infrastructure improvement projects.
• Perform network device upgrades, configuration changes and technology migrations.
• Prepare implementation and rollback plans.
• Conduct pre-change and post-change validation.
• Coordinate with internal teams, vendors and stakeholders during network implementations.
• Ensure all network changes are properly documented and communicated.

Incident & Problem Management

• Take ownership of complex network incidents through to resolution.
• Participate in Major Incident Management and provide technical updates.
• Perform detailed RCA for critical and recurring incidents.
• Identify opportunities to improve network reliability and reduce recurring incidents.
• Maintain technical knowledge articles and troubleshooting procedures.

Required Technical Skills

Networking

• Strong knowledge of TCP/IP, DNS, DHCP, NAT, VLAN, STP, QoS, VPN and network security.
• Strong hands-on experience with routing and switching.
• Good knowledge of BGP and OSPF.
• Strong troubleshooting skills using packet captures and network diagnostic tools.
• Experience with network monitoring and management platforms.

Cisco| Routing, switching, Catalyst/Nexus

Fortinet| FortiGate, Firewall, VPN, Security Policies

Palo Alto| NGFW, Security Policies, VPN, NAT

Juniper| Routing, Switching and Troubleshooting

Cisco Meraki| Switching, Wireless, Security Appliance

UniFi| Switching, Wireless and Network Management

Experience across multiple vendors is highly preferred.

Qualifications & Experience

• Diploma or Degree in IT, Computer Science, Networking or a related discipline.
• 5-8+ years of network engineering experience, with strong L3 troubleshooting experience.
• Hands-on experience supporting enterprise network environments.
• Experience working in a multi-vendor network environment.
• CCNP, JNCIP, Fortinet, Palo Alto or equivalent certifications are preferred.
• ITIL experience and knowledge of Incident, Problem and Change Management processes.
• Experience supporting regional or global environments is an advantage.
• Strong technical troubleshooting and analytical skills.
• Strong ownership and accountability.
• Able to independently troubleshoot complex network issues.
• Strong communication and stakeholder-management skills.
• Able to work effectively under pressure during major incidents.
• Good documentation and reporting skills.
• Proactive approach to network monitoring and problem prevention.
• Ability to mentor and provide technical guidance to L1/L2 engineers.
• Support enterprise and regional network infrastructure.
• Participate in on-call and after-hours support
• Support planned maintenance and network changes outside business hours.
• Participate in Major Incident Management and technical bridge calls.
• Work with regional/global teams across different time zones.
• Occasional travel to offices or data centres may be required.