L2/L3 Network Technical Support Engineer

Role Overview

We are looking for an experienced L2/L3 Network Technical Support Engineer to provide post

launch technical support for a broadband service provider’s network and services. The role will

be responsible for diagnosing and resolving complex network issues across broadband access,

IP, transport, and service layers.

The ideal candidate is a hands-on network engineer who can dig deep into network incidents,

isolate the specific fault domain, analyze network behavior and traffic, identify root causes, and

drive issues through to resolution. This role requires strong troubleshooting skills and the ability

to work across multiple network domains, including access, aggregation, routing, IP services,

and customer connectivity.

The engineer will work closely with NOC, network engineering, operations, architecture, service

assurance, vendors, and other technical teams to resolve production issues and improve

network stability after launch.

Key Responsibilities - L2/L3 Network Troubleshooting

• Provide L2/L3 technical support for production broadband network issues following service

launch.

• Troubleshoot complex incidents involving customer connectivity, service degradation, packet

loss, latency, routing, reachability, and network performance.

• Analyze issues across the network stack to determine whether the problem originates in the

access, aggregation, transport, IP, routing, service, or customer-premises domain.

• Perform detailed fault isolation and identify the specific network element, interface, route,

configuration, protocol, or service component contributing to an incident.

• Troubleshoot Layer 2 technologies such as VLANs, QinQ, Ethernet, ARP, MAC learning, STP,

and related access/aggregation technologies.

• Troubleshoot Layer 3 technologies including IPv4/IPv6, BGP, OSPF/IS-IS, routing policies, VRFs,

DHCP, DNS, NAT, and IP connectivity.

• Analyze packet captures, network logs, alarms, counters, routing tables, interface statistics,

and telemetry to identify root causes.

• Perform hands-on troubleshooting using CLI and network management/monitoring tools.
• Validate suspected issues by testing network paths, interfaces, routes, configurations, and

service dependencies.

• Support troubleshooting of broadband subscriber connectivity and service issues, including

DHCP/IP address assignment, authentication, routing, DNS, CGNAT, and Internet reachability, as

applicable to the network architecture.

• Correlate customer-impacting symptoms with network-level events and infrastructure faults.

Incident & Problem Management

• Own or contribute to resolution of complex L2/L3 production incidents.
• Work with NOC teams to investigate incidents that cannot be resolved through standard

operational procedures.

• Determine the appropriate escalation path and engage network engineering, architecture,

vendors, or other technical teams when required.

• Drive incidents toward resolution rather than simply escalating them.
• Conduct root-cause analysis for recurring or high-impact network problems.
• Develop and document troubleshooting procedures, known-error articles, and operational

runbooks.

• Identify opportunities to improve network monitoring, alarms, automation, and operational

processes based on recurring issues.

• Support post-incident reviews and provide technical recommendations to prevent recurrence.

Network Operations & Engineering Collaboration

• Collaborate with network engineering teams on complex production issues and configuration

changes.

• Validate network changes and troubleshoot issues following software upgrades, configuration

changes, migrations, or new service launches.

• Support network equipment and service troubleshooting across routers, switches, broadband

access equipment, aggregation devices, and IP infrastructure.

• Work with equipment and technology vendors to investigate hardware, software, protocol,

and interoperability issues.

• Provide technical input into network design improvements based on production support

experience.

• Participate in planned maintenance and change activities when required.
• Support troubleshooting during critical incidents and service-impacting events.

Required Technical Skills

• Strong hands-on experience troubleshooting Layer 2 and Layer 3 networks in a production

environment.

• Strong understanding of TCP/IP, Ethernet, VLANs, ARP, DHCP, DNS, IPv4/IPv6, routing, and IP

connectivity.

• Experience troubleshooting routing protocols such as BGP and OSPF/IS-IS.
• Experience with VRFs, routing policies, NAT/CGNAT, QoS, and IP service delivery.
• Ability to use network device CLI to investigate configuration and operational state.
• Strong understanding of packet flows and ability to trace a problem hop-by-hop through the

network.

• Experience using packet capture and analysis tools such as Wireshark/tcpdump.
• Experience interpreting network monitoring data, logs, alarms, interface counters, routing

tables, and telemetry.

• Ability to distinguish between customer/device issues, access-network issues, transport

issues, IP/routing issues, and application/service issues.

• Strong analytical and problem-solving skills with the ability to work from symptoms to root

cause.