Senior Network and Security Engineer

1. Enterprise Networking

• Design implement support and maintain LAN WAN WLAN and datacentre network infrastructure.

• Support enterprise switching with a strong focus on Extreme Networks platforms.

• Configure and maintain VLANs trunks STP redundancy link aggregation and resilient Layer 2 designs.

• Handle advanced routing and switching (OSPF BGP static routing route redistribution high availability failover).

• Troubleshoot performance latency packet loss routing STP and connectivity issues.

• Act as an escalation point for complex network incidents and recurring issues.

• Contribute to network architecture decisions standards lifecycle refresh and operational improvements.

2. Extreme Networks Switching

• Configure troubleshoot and maintain Extreme Networks switches in production and datacentre environments.

• Support switch stacks chassis edge core and aggregation layer configurations.

• Maintain resilient connectivity via trunking link aggregation STP tuning redundant uplinks and failover paths.

• Investigate switch port errors interface utilisation duplex/speed mismatches VLAN mismatches and MAC learning issues.

• Maintain consistent configuration standards and back up switch configurations.

• Support planned maintenance firmware upgrades configuration changes and switch replacements.

3. Firewall and Network Security (FortiGate Essential)

• Configure manage and maintain FortiGate firewalls across the enterprise.

• Own firewall policy and rule management (rule creation optimisation cleanup NAT UTM profiles security policies).

• Configure and troubleshoot VPN solutions (site-to-site remote access third-party cloud connectivity).

• Monitor firewall health logs sessions interface utilisation VPN tunnels and security events.

• Investigate and resolve firewall-related incidents affecting applications users systems vendors or cloud connectivity.

• Support firewall hardening segmentation least-privilege access and policy governance.

• Support security audits evidence gathering compliance requirements and remediation in a regulated financial services environment.

• Work with FortiManager and FortiAnalyzer for centralised policy management reporting logging and visibility.

• Experience with IPS IDS SSL inspection web filtering application control and security event investigation is advantageous.

4. Azure Networking and Hybrid Cloud Connectivity

• Demonstrate practical Azure networking knowledge (VNets subnets NSGs route tables Azure DNS private connectivity hybrid access).

• Support hybrid networking between on-premises infrastructure and Microsoft Azure.

• Troubleshoot Azure network routing name resolution firewall NSG private endpoint and hybrid connectivity issues.

• Support Microsoft 365 Teams Exchange Online and Azure service connectivity from a firewall/network perspective.

• Work closely with cloud server security and application teams to ensure secure resilient and well-documented cloud network architecture.

5. Monitoring Alerting and Observability

• Monitor network firewall wireless cloud connectivity and infrastructure health using enterprise tools.

• Investigate and resolve alerts related to availability firewall health interface utilisation routing stability VPN wireless performance and security events.

• Build maintain and improve dashboards alert thresholds operational reports and health checks.

• Perform trend analysis and capacity planning to identify growth availability performance and resilience risks.

• Maintain monitoring coverage for routers switches firewalls wireless VPNs links and cloud network services.

• Work with SNMP syslog ICMP checks service checks log forwarding and alert escalation processes.

• Experience with Nagios is advantageous; exposure to PRTG SolarWinds Zabbix FortiAnalyzer FortiManager or Azure Monitor is also valuable.

• Contribute to proactive monitoring improvements and service stability initiatives.

6. Wireless and Edge Networking

• Design deploy support and troubleshoot enterprise WiFi (including high-density office environments).

• Support secure wireless authentication (WPA2 WPA3 802.1x).

• Troubleshoot wireless performance coverage roaming interference and authentication issues.

• Maintain wireless standards SSID configuration guest access controls and secure segmentation.

• Work with network access controls and secure edge access where applicable.

7. Datacentre DR and Resilience

• Support datacentre and DR network connectivity with a focus on availability resilience and failover readiness.

• Support redundant network paths firewall failover routing failover VPN resilience and DR network testing.

• Participate in change planning maintenance windows infrastructure refreshes datacentre moves and DR exercises.

• Assist with root-cause analysis document lessons learned and drive practical remediation actions.

8. Operations Incident Response and Collaboration

• Provide day-to-day support for network firewall wireless VPN and hybrid connectivity operations.

• Respond to incidents in a calm structured and methodical manner (especially during outages or security events).

• Participate in planned maintenance windows and after-hours support as required.

• Work closely with server virtualisation database application security cloud and service desk teams.

• Work with external vendors ISPs carriers and technology partners to resolve incidents and deliver changes.

• Support change control impact analysis rollback planning implementation plans and post-change validation.

• Drive continuous improvement by identifying recurring issues and improving operational standards.

9. Documentation Standards and Knowledge Sharing

• Keep network and firewall documentation accurate and current (diagrams IP ranges VLANs circuits firewall rules VPNs configs).

• Maintain practical standards for network firewall monitoring and Azure networking.

• Document operational procedures runbooks troubleshooting guides and support handover notes.

• Share knowledge with junior engineers and contribute to a more mature infrastructure operations environment.

• Ensure configuration backups change records and operational documentation are kept up to date.

• At least 7 years of experience in enterprise network engineering.

• Strong hands-on FortiGate firewall administration policy management VPN NAT and troubleshooting.

• Proven experience supporting Extreme Networks switching environments.

• Strong routing/switching knowledge (VLANs trunks STP OSPF BGP VRRP or similar HA Layer 2/3 design).

• Strong firewall rule management network security segmentation and connectivity troubleshooting.

• Experience supporting enterprise datacentre connectivity high availability designs and production incident response.

• Practical experience with monitoring alerting network health checks and operational reporting.

• Required working knowledge of Azure networking and hybrid cloud (VNets NSGs routing VPN private connectivity).

• Ability to communicate clearly with technical and non-technical stakeholders.

• Strong documentation discipline and attention to detail.

• Fortinet NSE4 / NSE5 (or current Fortinet equivalent).

• Extreme Networks certification (advantageous).

• Microsoft Certified: Azure Network Engineer Associate (AZ-700) (advantageous).

• CCNP Enterprise CCNP Security or equivalent practical experience.

• ITIL Foundation (advantageous).