Senior Network & Security Engineer

Job description

About This Role: The Senior Network and Security Engineer is responsible for the design, implementation, automation, security, and operational support of Eir's enterprise and datacentre network infrastructure. This role combines solution design, project delivery, operational ownership, technical leadership, and mentorship. Participation in an on-call support rota for business-critical services is a core requirement. Expectations From The Role: Key Responsibilities Design, implement and support enterprise, datacentre, cloud-connected and security infrastructure. Act as technical design authority for network and security components of infrastructure projects. Design and support Cisco Nexus, VXLAN EVPN, SDN, NFV, NDFC/DCNM, DMZ, firewall, load-balancing and secure access solutions. Support datacentre migrations, disaster recovery initiatives, infrastructure upgrades and technology refresh programmes. Manage and support Cisco ASA, FTD/FMC, ISE, TACACS+, AnyConnect, Cisco Secure Access (Proxy/SSE), RSA Authentication Manager and Citrix ADC platforms. Develop firewall policies, VPNs, NAT, segmentation and access-control frameworks. Develop automation using Python, Ansible, Git, REST APIs, NETCONF/YANG, CI/CD and Infrastructure-as-Code. Support observability platforms including Grafana, Prometheus, ELK, NetFlow and MDT. Provide technical leadership, mentoring and continuous improvement across the team. Operational Responsibilities Support enterprise WAN, LAN, wireless, datacentre and security infrastructure. Act as an escalation point for complex incidents. Troubleshoot routing, switching, firewall, authentication, VPN, proxy, load-balancing and application connectivity issues. Manage infrastructure changes through governance and change-control processes. Conduct packet captures, root-cause investigations and service restoration activities. Maintain automation, monitoring, compliance, documentation and operational tooling. Work closely with vendors, service providers and internal stakeholders. On-Call & Service Ownership Participation in a formal on-call rota is mandatory. Responsibilities include major incident response, critical infrastructure fault resolution, emergency changes, security incidents, vendor escalations and post-incident analysis. Candidates must demonstrate strong ownership, accountability and the ability to independently manage issues through to resolution. Requirements For A Successful Application: Required Experience & Skills Minimum 10 years experience in enterprise, datacentre, telecommunications or large-scale network environments. Proven experience designing, implementing and supporting enterprise and datacentre infrastructure. Strong knowledge of routing, switching, OSPF, EIGRP, BGP, MPLS, QoS, VLANs, STP, DHCP, DNS and IP addressing. Strong knowledge of VXLAN EVPN, SDN, NFV, network virtualisation, DMZ architectures, IPSec, ACLs, VPNs, IPS/IDS, segmentation and access control. Hands-on experience with Cisco routing, switching, Nexus, ASA, FTD/FMC, ISE, TACACS+ and AnyConnect platforms. Experience with Cisco Secure Access (Proxy/SSE), Citrix ADC / NetScaler, RSA Authentication Manager, Huawei and Dell networking platforms. Experience with data centre switching technologies including Cisco Nexus and VXLAN EVPN fabrics. Experience with monitoring, telemetry and observability platforms. Strong troubleshooting, communication and stakeholder engagement skills. Preferred Qualifications Cisco CCNP, CCIE, or demonstrated equivalent expert-level network design, implementation and operational experience. Experience within telecommunications, managed services or large enterprise environments. Strong Python and Ansible automation experience. Experience with Infrastructure-as-Code, Git, CI/CD and network programmability. Experience operating VXLAN EVPN fabrics using NDFC/DCNM, Ansible Collections (or equivalent), or similar controller-driven architectures. Experience with Grafana, Prometheus, ELK, telemetry platforms and operational analytics. Knowledge of AI-assisted operational tooling and modern datacentre environments. Success Profile A senior engineer with deep networking and security expertise, strong operational ownership, automation capability and technical leadership, capable of delivering projects, supporting critical production environments and driving continuous improvement. Others: About eir Our purpose is to connect for a better Ireland. Our ambition is to be the number one choice for telecommunications and technology solutions, delivering for our customers today and into the future. Our new values and behaviours reflect both who we are and who we strive to become. They are the way that we bring our purpose to life in eir. We are committed to creating an inclusive and supportive work environment. If you require any reasonable adjustments during the application or interview process, please let us know, and we will work with you to meet your needs. If successful in the interview process, eir reserves the right to conduct appropriate suitability checks in relation to prospective employees including but not limited to reference checking and/or other searches using publicly available information. Apply Now!