Job Summary

Job Description: Mainframe Network Engineer / SpecialistRole SummaryWe are looking for an experienced Mainframe Network Engineer / Specialist to support the administration, availability, performance, security, connectivity, and modernisation of enterprise IBM Z networking environments. The role requires strong hands-on expertise in z/OS Communications Server, TCP/IP, VTAM/SNA, network configuration, troubleshooting, resiliency, security, and performance management.The individual will work closely with Mainframe infrastructure, network, security, application, middleware, operations, and vendor teams to ensure highly available, secure, and resilient connectivity for business-critical Mainframe platforms.

Key Responsibilities

Key ResponsibilitiesInstall, configure, maintain, upgrade, and support z/OS Communications Server and associated Mainframe networking components.Administer and troubleshoot TCP/IP, VTAM, SNA, Enterprise Extender, OSA, HiperSockets, and related IBM Z networking technologies.Configure and maintain TCP/IP profiles, network interfaces, routes, ports, resolver configurations, VIPA/DVIPA, and network connectivity within z/OS environments.Manage VTAM configurations, including major nodes, application definitions, cross-domain resources, and network connectivity.Support high-availability and workload-distribution configurations using technologies such as DVIPA, Sysplex Distributor, VIPA Takeover, and dynamic routing.Monitor Mainframe network availability, utilisation, capacity, latency, connectivity, and performance and proactively address potential issues.Perform problem determination for network-related incidents using z/OS system commands, Communications Server diagnostics, packet traces, logs, SMF records, network traces, and monitoring tools.Support network connectivity for Mainframe subsystems and middleware including CICS, Db2, IMS, IBM MQ, FTP/SFTP, Connect:Direct, web services, APIs, and application interfaces, depending on the environment.Configure and support secure Mainframe communications using TLS/SSL, AT-TLS, digital certificates, RACF key rings, encryption, and secure network protocols.Support DNS, name resolution, routing, firewall, proxy, load-balancing, and connectivity requirements in collaboration with enterprise network and security teams.Support IBM Z hardware network connectivity including OSA-Express, HiperSockets, LPAR connectivity, and HMC-related network considerations.Participate in IPL, DR exercises, resiliency testing, network failover, business-continuity testing, and recovery activities.Support software maintenance, upgrades, PTF application, lifecycle activities, and compatibility assessments related to z/OS Communications Server and networking components.Develop and maintain REXX, JCL, scripts, or other automation to improve network monitoring, diagnostics, configuration, and operational efficiency.Maintain technical documentation including network diagrams, configuration records, SOPs, operational procedures, recovery procedures, and audit evidence.Collaborate with Mainframe system programmers, enterprise networking, security, application, middleware, storage, automation, and service-management teams for incident, problem, change, and service-improvement activities.Support network security reviews, vulnerability remediation, compliance requirements, certificate renewals, and security-hardening activities.Identify opportunities for automation, network modernisation, observability, security improvement, and operational optimisation across the Mainframe network environment.

Skill Requirements

Required Technical SkillsStrong hands-on knowledge of IBM z/OS Communications ServerTCP/IP on z/OSVTAM / SNA networkingEnterprise Extender (EE)TCP/IP profile configuration, routing, interfaces, ports, and network servicesVIPA / DVIPA, Sysplex Distributor, and high-availability networking conceptsOSA-Express and HiperSocketsDNS and z/OS resolver configurationTLS/SSL and Application Transparent TLS (AT-TLS)RACF key rings, digital certificates, and secure communications conceptsNetwork diagnostics and troubleshooting using packet traces, logs, system commands, SMF records, and monitoring toolsKnowledge of networking requirements for CICS, Db2, IMS, IBM MQ, FTP/SFTP, Connect:Direct, and other Mainframe servicesTSO/ISPF and JCLREXX / scripting and operational automationKnowledge of IP routing, firewalls, ports, load balancing, network segmentation, and security conceptsIncident, problem, and change managementStrong troubleshooting and root-cause-analysis skillsPreferred SkillsExposure to one or more of the following would be advantageous:IBM Z hardware, LPAR and PR/SM conceptsParallel Sysplex and Sysplex networkingCICS, Db2, IMS, IBM MQHMC and OSA configuration conceptsSNA, APPN, HPR and Enterprise ExtenderFTP, SFTP, FTPS, Connect:Direct and managed file-transfer technologiesNetwork Management Interface (NMI), SMF and network-monitoring toolsMainframe network monitoring, performance, and observability solutionsRACF, digital certificates, PKI, TLS, AT-TLS, ICSF, and encryption technologiesEnterprise network technologies and platforms such as DNS, firewall, proxy, load balancer, VPN, and IPAMDisaster recovery, network resiliency, business continuity, and failover testingAnsible, Python, Git, REST APIs, or DevOps automation in a Mainframe environmentMainframe integration with distributed, hybrid-cloud, API, and modern application environmentsMainframe network security, segmentation, Zero Trust, and security-hardening concepts

Other Requirements

ExperienceRelevant hands-on experience in Mainframe network engineering, z/OS Communications Server administration, infrastructure support, or network operations.Experience supporting business-critical enterprise Mainframe environments with high availability and resiliency requirements.Experience administering and troubleshooting TCP/IP, VTAM/SNA, OSA, DVIPA, Sysplex networking, and secure Mainframe connectivity.Experience supporting network upgrades, connectivity changes, incident resolution, performance analysis, DR, and resiliency activities.Experience working with network security, TLS/SSL, certificates, firewall connectivity, and secure communication requirements.Experience working within structured ITIL-based Incident, Problem, Change, and Release Management processes.Desired ProfileStrong analytical and problem-solving capability.Ability to independently troubleshoot complex Mainframe network, connectivity, and performance issues.Strong understanding of enterprise networking concepts and their implementation within IBM Z environments.Good written and verbal communication skills.Comfortable working with global Mainframe, network, security, application, middleware, infrastructure, and vendor teams.Strong focus on availability, resiliency, security, performance, documentation, automation, and continuous improvement.Ability to coordinate complex connectivity issues across Mainframe and distributed network environments.