Network Engineer

Infinity Quest; Sheffield; On-site; GBP 70,000 - 95,000; Full time

Job summary

Infinity Quest is seeking a network and OT security engineer in the United Kingdom to design, implement, and operate Cisco-based networks across IT/OT environments.

The role requires expertise in SD-WAN, SDA fabric, OT protocols, and industrial cybersecurity frameworks, with scripting and automation to improve provisioning and operations.

Qualifications

• Strong expertise with Cisco Catalyst IOS-XE, VLANs, STP/RSTP and QoS.
• Experience with Cisco SD-WAN and SDA fabric design and operations.
• OT/IT DMZ design, Purdue model and IT/OT security concepts.
• Familiarity with OT protocols such as Modbus, DNP3, EtherNet/IP, PROFINET, IEC 61850, OPC-UA.
• Scripting in Python or Bash for network automation and provisioning with Terraform.
• Exposure to CI/CD tooling (GitLab CI, GitHub Actions, Jenkins).
• Experience with Cisco ISE for AAA, profiling, and TrustSec; RESTCONF/NETCONF interfaces.
• Knowledge of industrial cybersecurity frameworks (IEC 62443, NIST SP 800-82, NIS2).
• SCADA/ICS familiarity (Ignition, Wonderware, Siemens TIA Portal).

Skills

Cisco Catalyst IOS-XE

VLANs

STP/RSTP

QoS

SD-WAN

SDA fabric

OT network

Modbus

DNP3

OPC-UA

Terraform

GitLab CI

Python

Bash

Network troubleshooting

Cisco ISE

TrustSec

RESTCONF/NETCONF

NIST SP 800-82

IEC 62443

SCADA/ICS

Tools

Cisco NSO

Job description

• Strong expertise with Cisco Catalyst switching (IOS-XE), VLANs, STP, RSTP, port security, and Qos.


• Practical experience with Cisco SD-WAN / Catalyst SD-WAN) - policy templates, VPN segmentation, and WAN edge configuration.


• Hands-on experience with Cisco SD-Access (SDA) fabric design, commissioning, and operations.


• Working knowledge of Cisco Catalyst Centre - device management, assurance, and automation workflows.


• Understanding of OT network architecture, including the Purdue Model and IT/OT DMZ design.


• Familiarity with OT protocols: Modbus, DNP3, EtherNet/IP, PROFINET, IEC 61850, or OPC-UA.


• Experience writing Terraform configurations for infrastructure provisioning


• Exposure to CI/D tooling (GitLab CI, GitHub Actions, Jenkins, or equivalent).


• Scripting proficiency in Python and/or Bash for network automation tasks.


• Strong troubleshooting skills across Layers 2-7.


• Experience with Cisco ISE (Identity Services Engine) for AAA, profiling, and TrustSec.


• Knowledge of Ansible or Terraform for network configuration management.


• Familiarity with Cisco NSO or RESTCONF/NETCONF interfaces.


• Exposure to industrial cybersecurity frameworks: IEC 62443, NIST SP 800-82, or NIS2.


• Experience with SCADA/ICS systems (e.g., Ignition, Wonderware, Siemens TIA Portal, Rockwell FactoryTalk).


• Familiarity with network monitoring tools