Eric Zeigenbein

Senior Systems & Network Engineer (Remote)

St. Louis, Missouri, United States

Contact: [email protected] | LinkedIn

Professional Summary

Senior Systems & Network Engineer with 20+ years of experience delivering secure, resilient, and automated infrastructure across enterprise environments. Expertise spans Linux/Windows administration, virtualization, cloud networking, and secure network design. Skilled in Fortinet FortiGate deployments (hardware and VM, on-prem and Azure), SentinelOne EDR incident response, LAN modernization with Cisco routing/switching, automation with Python (including AI-assisted coding)/Bash/PowerShell, and advanced monitoring workflows. Experienced across both Layer 2 (switching/VLANs) and Layer 3 (routing, firewalls, OSPF/BGP fundamentals), consistently ensuring business environments remain stable, compliant, and secure. Adept at collaborating with cross-functional teams, performing root-cause analysis, and developing in-house tools to streamline operations.

Core Competencies

  • Networking (L2/L3): VLAN design & segmentation, trunking (802.1Q), inter-VLAN routing (SVIs), STP/RSTP, LACP/EtherChannel, DHCP relay, NAT, static routing, OSPF/BGP fundamentals, QoS basics.
  • Security: Fortinet FortiGate policy design (zones, objects, NAT), IPsec site-to-site & remote-access VPNs, SSL inspection basics, logging/alerts, change control, endpoint security with SentinelOne EDR.
  • Platforms & Vendors: Fortinet FortiGate (hardware/VM), Cisco Catalyst/Nexus (routing/switching), Azure networking (VNets, subnets, UDRs), VMware vSphere/ESXi, Hyper-V.
  • Systems: Linux (Debian/Ubuntu), Windows Server (AD/DNS/DHCP), file/services hardening, backup/restore.
  • Automation, Monitoring & Ticketing: Bash/PowerShell scripting; Python for custom in-house and client-specific solutions (library-based + AI-assisted coding); Zabbix, Nagios; packet capture/analysis with FortiOS diag sniffer, tcpdump, Wireshark; ticketing workflows with ServiceNow and ConnectWise.
  • Cloud: Azure (FortiGate-VM, VNets, route tables, IPsec to on-prem), AWS (core IaaS familiarity).
  • Application Support: Log review for NGINX, IIS, Apache, syslog; database queries; integrations across hybrid on-prem/cloud environments.
Incident Response Root Cause Analysis Escalation Workflow 24x7 Support ServiceNow ConnectWise Layer 2 Layer 3 VLAN / 802.1Q Fortinet FortiGate Cisco Routing & Switching Azure Networking SD-WAN (Fortinet) Wireshark SentinelOne EDR Python Tools

Professional Experience

Senior Systems & Network Engineer

EIS Consulting Group | April 2022 – Present

  • Provisioned Fortinet FortiGate firewalls from zero-touch setup through production, implementing base hardening, policy objects, NAT, and IPsec site-to-site connectivity.
  • Implemented FortiGate-VM in Azure: VNets, subnets, UDRs/route tables, public/private IPs, and IPsec links to on-prem edges; validated routing and failover using diag debug flow and packet captures.
  • Modernized LANs with Cisco routing/switching: VLAN segmentation, trunking, SVIs, STP tuning, EtherChannel, DHCP relay; documented L2/L3 topologies and migration steps.
  • Troubleshot OSPF/BGP adjacencies and routing policies with vendor TAC for enterprise deployments.
  • Deployed and managed SentinelOne EDR for incident response, remediation, and forensic investigations.
  • Developed Python automation and troubleshooting tools (AI-assisted and library-based) to streamline enterprise network and system support.
  • Created standard templates for firewall and switch deployments to reduce drift and speed up maintenance.
  • Automated health checks, backups, and configuration comparisons with Bash/PowerShell/Python scripts.
  • Provided 24/7 on-call support, incident triage, ServiceNow/ConnectWise ticketing, and vendor escalation.
  • Worked with enterprise backup/storage (Veeam, Barracuda, SAN/NAS) and forensic recovery strategies.

Systems Administrator

GOT Systems | May 2017 – October 2023

  • Maintained nationwide Windows/Linux environments with a focus on uptime, performance, and security.
  • Led Cisco router/switch refresh efforts: VLAN design, trunking consistency, port security, and inter-VLAN routing.
  • Implemented VPN connectivity for remote offices and users; audited and tuned firewall policies to least privilege.
  • Built and deployed Python applications/scripts for client solutions, monitoring, and system integrations (including AI-assisted coding).
  • Deployed endpoint security solutions, patch management, and malware protection with SentinelOne EDR.
  • Performed troubleshooting and incident response in a small-team setting without formal ticketing systems.
  • Automated recurring tasks with Bash/PowerShell/Python to reduce operational workload and improve monitoring quality.

Litigation Application Support Engineer

Epiq Systems | March 2015 – May 2017

  • Supported e-Discovery platforms (Nuix, Relativity, LAW PreDiscovery) with data handling, validation, and chain-of-custody documentation.
  • Worked with infrastructure teams to troubleshoot storage, permissions, and Windows Server dependencies for legal productions.

Technical Support Agent

H&R Block | May 2014 – March 2015

  • Supported proprietary financial applications and hybrid server environments across distributed offices; emphasized clear root-cause analysis and user impact mitigation.

Customer Service Representative

General Dynamics IT | July 2012 – October 2014

  • Delivered secure, high-volume support for Medicare beneficiaries using controlled-access systems, maintaining confidentiality and compliance requirements.

Networking Snapshot

Education

Missouri State University
Field: Information Systems (Relevant Coursework)

Technical Skills