Senior OT Network Engineer: Secure, Reliable Networking

Nexon Asia Pacific; Sydney; On-site; AUD 120,000 - 170,000; Full time

Job summary

Nexon Asia Pacific is seeking an experienced Level 3 Network Engineer to deliver advanced network support across a critical OT environment in Sydney, Australia. The role emphasizes enterprise networking, security, load balancing, proxy services, and time synchronization.

You will collaborate with IT, OT, engineering, cybersecurity, and operations teams to ensure secure, reliable, and highly available network services while supporting incident response and continuous improvements.

Qualifications

• 5+ years in network engineering or a similar technical role.
• Proven Level 3 network troubleshooting and support experience.
• Strong hands-on experience with Dell PowerSwitch or equivalent.
• Strong experience with Palo Alto Firewalls.
• Experience with F5 Load Balancers.
• Experience with Squid Proxy or equivalent proxy technologies.
• Experience with Trimble GPS Clock, NTP, PTP, or network time synchronisation.
• Strong knowledge of TCP/IP, VLANs, routing, DNS, DHCP, VPNs, NAT, and network security.
• Experience with network monitoring and diagnostic tools such as Wireshark and tcpdump.
• Strong problem-solving and root-cause analysis skills.
• Ability to work independently and support critical operational environments.
• Experience in OT, utilities, energy, mining, manufacturing, or other critical infrastructure is highly desirable.

Responsibilities

• Provide Level 3 support for complex network incidents, problems, and outages.
• Configure, maintain, and troubleshoot Dell PowerSwitch network infrastructure.
• Administer and troubleshoot Palo Alto Firewalls, including policies, NAT, VPNs, and routing.
• Support F5 Load Balancers, including virtual servers, pools, health monitors, and SSL/TLS.
• Support and troubleshoot Squid Proxy services and configurations.
• Maintain and troubleshoot Trimble GPS Clock and network time synchronisation services.
• Troubleshoot TCP/IP, DNS, DHCP, VLANs, routing, switching, VPNs, and network connectivity.
• Perform root-cause analysis and implement permanent solutions.
• Support network security, segmentation, hardening, and vulnerability remediation.
• Perform network installations, upgrades, maintenance, and technology refresh activities.
• Maintain network documentation, diagrams, configurations, and operational procedures.
• Work with vendors and internal teams to resolve complex technical issues.

Skills

5+ years in network engineering

Level 3 troubleshooting

Independent worker

OT/critical infrastructure exposure

Strong problem-solving

Network security awareness

Tools

Dell PowerSwitch

Palo Alto Firewall

F5 Load Balancer

Squid Proxy

Trimble GPS Clock / NTP / PTP

Wireshark

tcpdump

DNS/DHCP/VPNs

VLANs & routing

Job description

Nexon Asia Pacific is seeking an experienced Level 3 Network Engineer to deliver advanced network support across a critical OT environment in Sydney, Australia. The role emphasizes enterprise networking, security, load balancing, proxy services, and time synchronization.

You will collaborate with IT, OT, engineering, cybersecurity, and operations teams to ensure secure, reliable, and highly available network services while supporting incident response and continuous improvements.