Level 3 Network Engineer

About the Role

We are seeking an experienced Level 3 Network Engineer to join our IT Infrastructure team at our Central Islip office . In this role, you will be responsible for managing, designing, implementing, and troubleshooting complex network solutions with a focus on Cisco and Meraki technologies . You will act as the escalation point for Level 1 and 2 network support, ensure high availability and performance of network infrastructure, and participate in strategic network planning.

Key Responsibilities

• Serve as the subject matter expert (SME) for all Cisco and Meraki networking systems.
• Design, configure, and deploy enterprise-level LAN, WAN, and WLAN solutions.
• Monitor and optimize network performance using tools such as Cisco DNA Center, Meraki Dashboard, and SolarWinds.
• Respond to and resolve escalated network incidents and problems; lead root cause analysis.
• Maintain documentation for network architecture, topologies, and configurations.
• Collaborate with cross-functional teams on infrastructure projects and security initiatives.
• Assist in network upgrades, migrations, and expansion projects.
• Provide mentorship and technical guidance to junior network staff.
• Perform regular firmware upgrades, patch management, and compliance checks.
• Travel to remote offices and data centers for installations, audits, and troubleshooting (10 20%).

Required Qualifications

• 5+ years of hands-on experience in network engineering.
• Strong expertise in Cisco networking technologies (Catalyst, ISR/ASR, ASA/Firepower, Nexus).
• In-depth experience with Cisco Meraki products (MX, MR, MS).
• Proven experience with Layer 2 and Layer 3 networking, VLANs, routing protocols (OSPF, BGP, EIGRP), VPNs, NAT, QoS.
• Solid understanding of network security principles and firewalls.
• Familiarity with cloud networking (Azure/AWS) and SD-WAN solutions is a plus.
• Strong analytical and troubleshooting skills.

Preferred Certifications

• CCNP (Cisco Certified Network Professional) required.
• Meraki CMNA or ECMS certification is a plus.
• CCIE (optional but highly desirable).

Work Environment

• This is a full-time onsite role in our Central Islip office.
• Some regional travel (10 20%) to support remote sites and projects.
• Flexible schedule and after-hours support may be required during critical deployments or outages.

ATD Technology, LLC is a certified minority woman owned business that creates opportunities to match qualified individuals with client programs while meeting all parties' financial and technical goals. ATD is a full service provider with offerings in Contract, Permanent and Temp-to-Perm staffing solutions. We serve Fortune 1000, mid cap and small cap companies in the Commercial, Public and Government sectors.