3rd Line Network Support Engineer

CyberNorth; Gateshead; Hybrid; GBP 55,000 - 75,000; Full time

Job summary

Aspire Technology Solutions is seeking a highly experienced 3rd Line Network Support Engineer to own complex network faults and escalation across Fortinet, Extreme and Cisco environments. You will diagnose, fix and document root causes while mentoring junior engineers and coordinating with customers and internal teams.

You will design and deliver secure network changes, manage incidents under pressure, and continually improve architectures and automation to ensure top‑quality service delivery.

Qualifications

• Proven experience in a 3rd line, Senior or escalation level network role.
• Strong hands on experience with firewalls and network security.
• Advanced Fortinet FortiGate knowledge is a major advantage.
• Knowledge of Fortinet stack components FortiManager, FortiAnalyzer, FortiNAC.
• Experience with Extreme networking and Cisco routing/switching.
• Core networking skills: routing, switching, VLANs, VPNs, SD-WAN, TCP/IP.
• Ability to lead on complex faults and document work clearly.
• Clear written and verbal customer communication.
• Fortinet certifications or pursuit towards them is beneficial.

Responsibilities

• Act as final point of technical escalation for network and security incidents across Fortinet, Extreme, and Cisco environments.
• Design, configure and deliver network and security changes for a diverse customer base.
• Lead major incident diagnosis and resolution while keeping stakeholders informed.
• Identify opportunities to improve network designs and automation.
• Produce and maintain technical documentation and handover notes.
• Mentor 1st/2nd line engineers and grow the team's capability.
• Collaborate with customers to plan changes and manage risk to meet standards.
• Log and manage tickets, prioritise work, and meet SLAs.

Skills

Fortinet FortiGate

FortiManager

FortiAnalyzer

FortiNAC

Extreme networking

Cisco routing

Cisco switching

VPN

SD-WAN

TCP/IP

Network security

Firewall policy

Technical mentoring

Customer communication

Job description

At Aspire Technology Solutions, we are a leading UK provider of managed IT, cyber security and modern workplace solutions. We deliver cyber security, cloud, connectivity, managed services and unified communications solutions that help organisations get more from their technology – driving innovation, improving efficiency and enabling faster growth. Through strong partnerships, we help our customers work smarter, operate more efficiently and achieve better business outcomes, consistently adding value along the way.

Our mission: To deliver technology like no other!

We look for dynamic individuals who embrace technology, think differently, collaborate as team players, and are driven by continuous improvement with a focus on great results for our customers.

About the role

As a 3rd Line Network Support Engineer, you sit at the top of our technical escalation path. You will take ownership of the complex network and security faults that our 1st and 2nd line teams are unable to resolve and see them through to a fix.

You will work hands-on across our core technology stack, which is built around Fortinet and Extreme, with plenty of Cisco in the mix across our customer environments. Firewall work sits right at the heart of the role, so a strong grasp of Fortinet FortiGate and network security will really set you apart.

You will also be a trusted point of technical authority for the wider service desk, sharing knowledge, mentoring less experienced engineers and helping to lift the standard of everything we deliver. Clear communication matters just as much as deep technical skill, as you will be working with customers and internal teams to diagnose issues, agree the right approach and keep people informed until the work is done.

Communication with customers will take place over the phone and via email whilst utilising fault-finding programmes that assist you in diagnosing and fixing customer problems remotely. Customer service is key to success in the role – living our values are woven through everything we do to guarantee that our service delivery is second to none.

What you will be doing

• Acting as the final point of technical escalation for network and security incidents, taking ownership of complex faults raised by our 1st and 2nd line teams and resolving them through to root cause, across areas such as:
  • Fortinet firewalls and the wider Security Fabric, including FortiGate, FortiManager and FortiAnalyzer
  • Extreme switching and wireless infrastructure
  • Cisco routing and switching across a range of customer networks
  • Core networking such as routing, switching, VLANs, VPNs and SD-WAN
  • Network security, including firewall policy, VPN tunnels and traffic inspection
• Designing, configuring and delivering network and security changes for a large and diverse customer base, both remotely and as part of planned works.
• Leading the diagnosis and resolution of major network incidents, keeping a clear head under pressure to restore service while keeping customers and internal stakeholders updated throughout.
• Supporting continual improvement by spotting opportunities to strengthen network designs, tighten security and automate manual tasks.
• Producing and maintaining clear technical documentation, build standards and handover notes so that knowledge is shared properly across the team.
• Mentoring and supporting 1st and 2nd line engineers, sharing your knowledge and helping to grow the technical capability of the wider team.
• Working closely with customers and colleagues to plan changes, manage risk and deliver work that meets our standards first time.
• Logging and managing your tickets accurately, working to agreed SLAs and prioritising well while handling several pieces of work at once.

You will suit the role if you have

• Proven experience in a 3rd line, Senior or escalation level network role, ideally within a managed service provider or a similar multi-customer environment.
• Strong hands on experience with firewalls and network security. Advanced Fortinet FortiGate knowledge is a major advantage and is exactly the kind of experience we want to see.
• Good working knowledge of the wider Fortinet stack, such as FortiManager, FortiAnalyzer and FortiNAC.
• Experience with Extreme networking, or the confidence to get up to speed with it quickly.
• Strong Cisco routing and switching knowledge.
• A confident grasp of core networking, including routing, switching, VLANs, VPNs, SD-WAN and TCP/IP.
• The ability to take the lead on complex faults, think logically under pressure and work a problem through to its root cause.
• Clear and friendly communication, both written and verbal, with a genuine focus on looking after the customer.
• A methodical, well organised approach and the discipline to document your work as you go.
• We value real world experience first, but Fortinet certifications at FCP or FCSS level, or a genuine appetite to work towards them, would be great to see.
• Extreme certifications are useful too, though not essential.

Our values

We understand that you might not have all of the qualifications and experiences that we think are key to succeeding in this role therefore we provide continuous learning and development at Aspire which is at the heart of everything we do. As long as you are passionate, eager to learn and driven to be the best at what you do and live our values this role may be a fit for you.