Title:Lead IT Network Administrator, Network, Voice, AVKBR is seeking a Lead IT Network Administrator (Network, Voice & AV) to join our team supporting complex, mission critical IT infrastructure across enterprise and secure environments. This role is responsible for leading the administration, optimisation, and support of networking, voice, and audiovisual services, ensuring high levels of performance, security, and availability across multiple sites. The successful candidate will bring strong expertise in Cisco networking technologies, network security, cloud connectivity, and unified communications, while serving as a key technical escalation point for operational support and infrastructure projects.This is an exciting opportunity for an experienced IT professional to work with advanced networking, security, and collaboration technologies in a highly regulated environment. You will play a key role in maintaining resilient, secure, and high performing services, driving continuous improvement initiatives, and contributing to the delivery of critical business and operational outcomes across the organisation.This is a permanent, full-time position based in Aldershot, Basingstoke, Salisbury, Southampton, or Swindon. Only candidates with UK Citizenship and holding a BPSS or above should apply.In September 2025, KBR announced that we are spinning our Mission Technology Solutions business into a separate public company. This role will ultimately be part of the new company. The Mission Technology Solutions business partners with governments and defense, intelligence, space, aviation, and critical infrastructure customers to deliver high-end engineering, science, technology, and mission support solutions.Key ResponsibilitiesConfigure, administer, and optimize complex Cisco networking environments, including Cisco Identity Services Engine (ISE), Cisco Nexus Dashboard Fabric Controller (NDFC), Nexus switching, Leaf-Spine architectures, VXLAN, EVPN, and SD-WAN technologies (Cisco Viptela and Meraki).Manage enterprise routing and switching services across data centres, office locations, cloud platforms, and remote access environments.Administer and support secure network services including Palo Alto firewalls, network segmentation, access control policies, and remote connectivity solutions.Manage F5 BIG-IP load balancing platforms, including virtual servers, pools, health monitors, certificates, and traffic management policies.Support Microsoft Azure networking services, including virtual networks, subnets, network security groups, route tables, gateways, and hybrid cloud connectivity.Troubleshoot and resolve complex infrastructure, networking, and application connectivity issues across multiple technology domains.Analyse packet captures, traffic flows, monitoring alerts, and platform telemetry to identify root causes and implement corrective actions.Perform network upgrades, software patching, hardware refresh activities, lifecycle management, and capacity planning.Monitor network availability, performance, and utilization to ensure optimal service delivery and operational stability.Support backup, recovery, disaster recovery testing, high availability solutions, and operational resilience initiatives.Maintain network diagrams, configuration records, technical standards, and operational documentation.Participate in incident, problem, and change management activities to support reliable and secure service delivery.Collaborate closely with infrastructure, cybersecurity, cloud, application, and third party support teams to maintain secure and resilient services.Basic QualificationsEducation & ExperienceUK Citizenship is required.Current Baseline Personnel Security Standard (BPSS) clearance or higher.Strong hands on experience with Cisco networking technologies, including Nexus switching, Cisco ISE, SD-WAN, and modern data centre networking solutions.Experience supporting Cisco Nexus environments, including Leaf-Spine architectures, VXLAN, and EVPN technologies.Experience administering Cisco NDFC or equivalent data centre network management platforms.Experience supporting enterprise routing and switching technologies across large scale environments.Experience administering Palo Alto firewalls and enterprise network security solutions.Experience supporting F5 BIG-IP load balancers and Microsoft Azure networking services.Experience with network monitoring, traffic analysis, and packet capture tools.Proven ability to diagnose and resolve complex issues across network, cloud, and security platforms.Experience supporting resilience, business continuity, and disaster recovery initiatives.Skills & CompetenciesAdvanced knowledge of enterprise networking technologies, including BGP, OSPF, VLANs, VRFs, Spanning Tree Protocol, and link aggregation.Strong understanding of modern data centre networking concepts, including Leaf-Spine architectures, VXLAN, and EVPN.Knowledge of VPN technologies, network access control, authentication, authorization, and network security principles.Ability to analyse network performance, identify root causes, and implement effective remediation strategies.Strong understanding of operational best practices, including monitoring, patching, lifecycle management, documentation, and change control.Excellent troubleshooting and analytical skills within complex enterprise environments.Strong communication, documentation, and stakeholder engagement capabilities.Ability to work effectively within highly regulated and security conscious environments.Preferred QualificationsCisco certifications such as CCNP Enterprise, CCNP Data Center, or equivalent.Palo Alto Networks certifications or significant operational experience.F5 certification or extensive hands on BIG-IP LTM administration experience.Microsoft Azure networking certification or equivalent cloud networking expertise.Experience supporting Defence, Government, Aerospace, or other highly regulated environments.Experience with Cisco TrustSec, Security Group Tags (SGT), or identity based network segmentation.Experience with Azure ExpressRoute, cloud interconnects, and colocation facilities.Experience with automation and scripting technologies such as Python, Ansible, or Terraform.Experience supporting global enterprise networks across multiple locations and telecommunications providers.Exposure to Secure Access Service Edge (SASE), advanced network security technologies, or application delivery solutions.SummaryLocation: Leatherhead, Surrey, United KingdomType: Full time