Senior Network Security Engineer | Fortinet | Cisco | Firewall Consultant
Aktualisiert am 27.04.2026
Profil
Freiberufler / Selbstständiger
Remote-Arbeit
Verfügbar ab: 01.05.2026
Verfügbar zu: 100%
davon vor Ort: 100%
Fortinet
Network Security
Cisco
Firewall
Fortigate
IPsec
VPN
Netzwerkinfrastruktur
Remote Trouble Shooting
fortianalyzer
fortimanager

Einsatzorte

Einsatzorte

Cologne (+50km)
Deutschland, Schweiz, Österreich
möglich

Projekte

Projekte

2 years 1 month
2024-04 - now

Optimization & Administration Data Center Firewalls

Optimization & Administration Data Center Firewalls and Local Site Firewalls
  • Preparation of an firewall audit
  • Recommendation and implementation of optimization measures based on the audit
  • General Network Infrastructure Optimization Recommendations


Project DC-Firewall Policy-Cleanup:

  • Step 1 - Conception of the procedure
  • Step 2 - Classification of policies into sequence groups and splitting of general policies
  • Step 3 - Coordination with product owners about the upto- dateness of the ports/target servers
  • Step 4 - New sorting of the remaining policies


Project Development of a comprehensive threat protection strategy:

  • Step 1 - Re-assessment of the network architecture (including DMZ segmentation) to reduce the attack surface
  • Step 2 - Development and implementation of a companywide security strategy (including locations) based on the security audit carried out
  • Step 3 - Closing identified security gaps and introducing restrictive policies based on the principle of least privilege; Bridge to the Policy-Cleanup project
  • Step 4 - Construction of suitable UTM/NGFW security profiles (IPS/IDS, AV, web filter, app control) for each service/application
  • Step 5 - Selection of Policies for Tester Group
  • Step 6 - Activation of UTM profiles & accompanying log analysis; Screening for false positives & reporting
  • Step 7 - Fine-tuning or adaptation of UTM profiles
  • Step 8 - Go Live & Accompanying Log Analysis
  • Step 9 - Development of process guidelines


Administration of all FortiGates (>500) models 2601F / 60F:

  • Administration Policies / Approval of Approvals
  • Administration IPSec-S2S-Tunnel
  • Administration UTM: IPS, AV, SSL inspection, web filter, application control
  • Administration Interface
  • Administration Access Authorizations
  • Recommend & perform firmware upgrades


Administration FortiADC:

  • Creating, modifying and deleting virtual servers / server pools
  • Optimization of L4 & L7 load balancing
  • Monitoring & Optimization of Health Checks
  • Certificate management
  • General administration of partitions
  • Firmware upgrades


Administration EMS / FortiClient:

  • Recommending & Performing FCL Updates
  • Adminstration Web Filter Settings
  • Troubleshooting connection problems
  • Preparation for the switch from SSL VPN to IPSec


Administration FortiWeb:

  • Creation, deletion of new domains
  • Administration of policies
  • General Management Security Profiles
  • Certificate management
  • Troubleshooting Memory Bug


FortiManager

  • Integration of all firewalls into the FortiManager
  • General administration of the firewalls via the FM
  • Monitoring & Optimization


FortiAuthenticator:

  • General management of users
  • Administration of authentication methods
  • Troubleshooting Faulty HA Clusters
    • General Support Services / Troubleshooting Incidents
    • Regular firmware upgrades (PSIRT checks)
    • Security/Threat Analysis
    • Support for the SD-WAN pilot project

Large international corporation
1 year
2023-03 - 2024-02

Customer project planning of a new network architecture

  • Development of a new network infrastructure
  • Network Design Visio
  • Network segmentation and VLAN concept (BSI compliant)
  • Firewalling Concept
  • Creation of an IPAM
  • Planning Number of Access Points
  • Expense planning for the move
  • Review of procurements
Public Administration
11 months
2023-02 - 2023-12

Further development of the digital workplace of all employees

Further development of the digital workplace of all employees of the State of Berlin in the area of LAN and printers
  • Technical project management
  • Further development of the monitoring and security concept in the area of LAN (reporting via CheckMK, 802.1x-Auth)
  • Conception of location-flexible working in the LAN sector
  • Conception of the comprehensive administrative WLAN
  • Project management Implementation of pull printing in the area of printing (management of print jobs via central print servers, RFID card authentication)
  • Assessment of IT architecture requirements taking into account the eGovernment Act
Public Administration
6 months
2022-09 - 2023-02

Support for IT and redesign of the WLAN Infrastructure

  • Support of the IT department in support
  • Troubleshooting
  • Review of the redesign of the new Extreme WLAN infrastructure (complete replacement of the existing infrastructure, migration to a new controller)
Research Institute
6 months
2022-04 - 2022-09

IP address harmonization

  • Advice on migration procedures:
    • Advice on migrating services to the cloud
    • Review of the existing OBASHIs
    • Advice on migration strategy and corresponding scheduling based on the OBASHIs
  • Advice on address translation (=NAT) as an interim solution for the conversion to IPv6:
    • Parallel to the migration process: Analysis of communication links
    • Classification of communication links for which a NAT is required
    • Recommendation of the appropriate NAT strategy for the respective communication links
  • Review of the customer's network plans for security vulnerabilities
Public Administration
5 months
2021-12 - 2022-04

Support in the area of access LAN of the customer

  • Configuration and Administration of >1200 L2/L3 Devices (Cisco Catalyst 9200, 9300)
  • Construction and commissioning of new data centers for various customers
  • Improvement of customers' NAC infrastructure:
    • Prevention of spoofing attacks
    • Prevention of DoS and DDoS attacks
  • IPAM and Cisco ISE Administration for the ITZ Bund locations
  • Monitoring (Checkmk)
  • Troubleshooting in the area of Access LAN
  • Second/third-level support in the area of access LAN
Public Administration
7 months
2021-06 - 2021-12

Construction, commissioning and administration

Network Administrator
Network Administrator
  • Construction, commissioning and administration of new WLAN and LAN infrastructures (Cisco, Extreme/Aerohive); Support of >300 locations with large infrastructures
  • Network analyses / troubleshooting of performance problems (3rd level)
  • Plan and illuminate new wireless networks with Ekahau Site Survey
  • Management of access points via the cloud controller (Extreme Cloud IQ)
  • Creation of internal documentation (Confluence)
NetCologne IT-Services GmbH

Aus- und Weiterbildung

Aus- und Weiterbildung

2006 - 2007

Vocational training as a technical Communication assistants


2004 - 2005

Vocational College for Technology and Communication

Hohentwiel Vocational School Singen / Vocational College Technology & Media, BSZ Stockach


Key Focus:

  • Basics of network technology
  • Technical communication
  • Basics of programming in Java


Certifications

  • Fortinet NSE 4 FortiGate Administrator (FCP)
  • Fortinet Certified Associate (FCA),
  • Fortinet Certified Fundamentals (FCF),
  • Threat Landscape 2.0 Fortinet,
  • Cybersecurity 2.0 Fortinet,
  • Cisco Certified Network Associate (CCNA),
  • Extreme Wireless Cloud,
  • NAT Cisco Routers,
  • Network analysis with Wireshark

Position

Position

  • Network Security Engineer
  • Network Engineer

Kompetenzen

Kompetenzen

Top-Skills

Fortinet Network Security Cisco Firewall Fortigate IPsec VPN Netzwerkinfrastruktur Remote Trouble Shooting fortianalyzer fortimanager

Produkte / Standards / Erfahrungen / Methoden

IT ? Skills
  • Firewalling (Fortinet FortiGate)
  • FortiADC
  • FortiManager
  • FortiWeb
  • FortiFAC
  • FortiAnalyzer
  • FortiEMS
  • Patching/Network Building
  • Network Design
  •  Network Basics
  • Switching, Cisco (e.g. Catalyst 9200, 9300)
  • Routing, Cisco
  • Wi-Fi
  • NAC
  • Third-level support
  • Troubleshooting
  • General Project Management
  • Experience in the support of large-scale IT projects
  • Experience in the administration of complex infrastructures


Soft - Skills

  • Strong communication skills
  • Independent work
  • Analytical-Conceptual Thinking
  • Comprehension
  • Problem-solving skills
  • Organizational and leadership skills


Tools / Systems

  • ZTNA
  • SD-WAN
  • FortiGate
  • FortiADC
  • FortiWeb
  • FortiAnalyzer
  • FortiManager
  • FortiEMS
  • FortiFAC
  • Cisco Catalyst
  • Cisco ISE
  • IPAM systems
  • Check_mk
  • Ekahau Site Survey
  • Extreme Cloud IQ
  • incident handling via ticket systems (e.g. Jira, BMC-Remedy)
  • Wireshark
  • Nagios
  • MS Visio
  • Confluence
  • GenuGate
  • Python


more experiences

  • Sales
  • Experience as a manager












Einsatzorte

Einsatzorte

Cologne (+50km)
Deutschland, Schweiz, Österreich
möglich

Projekte

Projekte

2 years 1 month
2024-04 - now

Optimization & Administration Data Center Firewalls

Optimization & Administration Data Center Firewalls and Local Site Firewalls
  • Preparation of an firewall audit
  • Recommendation and implementation of optimization measures based on the audit
  • General Network Infrastructure Optimization Recommendations


Project DC-Firewall Policy-Cleanup:

  • Step 1 - Conception of the procedure
  • Step 2 - Classification of policies into sequence groups and splitting of general policies
  • Step 3 - Coordination with product owners about the upto- dateness of the ports/target servers
  • Step 4 - New sorting of the remaining policies


Project Development of a comprehensive threat protection strategy:

  • Step 1 - Re-assessment of the network architecture (including DMZ segmentation) to reduce the attack surface
  • Step 2 - Development and implementation of a companywide security strategy (including locations) based on the security audit carried out
  • Step 3 - Closing identified security gaps and introducing restrictive policies based on the principle of least privilege; Bridge to the Policy-Cleanup project
  • Step 4 - Construction of suitable UTM/NGFW security profiles (IPS/IDS, AV, web filter, app control) for each service/application
  • Step 5 - Selection of Policies for Tester Group
  • Step 6 - Activation of UTM profiles & accompanying log analysis; Screening for false positives & reporting
  • Step 7 - Fine-tuning or adaptation of UTM profiles
  • Step 8 - Go Live & Accompanying Log Analysis
  • Step 9 - Development of process guidelines


Administration of all FortiGates (>500) models 2601F / 60F:

  • Administration Policies / Approval of Approvals
  • Administration IPSec-S2S-Tunnel
  • Administration UTM: IPS, AV, SSL inspection, web filter, application control
  • Administration Interface
  • Administration Access Authorizations
  • Recommend & perform firmware upgrades


Administration FortiADC:

  • Creating, modifying and deleting virtual servers / server pools
  • Optimization of L4 & L7 load balancing
  • Monitoring & Optimization of Health Checks
  • Certificate management
  • General administration of partitions
  • Firmware upgrades


Administration EMS / FortiClient:

  • Recommending & Performing FCL Updates
  • Adminstration Web Filter Settings
  • Troubleshooting connection problems
  • Preparation for the switch from SSL VPN to IPSec


Administration FortiWeb:

  • Creation, deletion of new domains
  • Administration of policies
  • General Management Security Profiles
  • Certificate management
  • Troubleshooting Memory Bug


FortiManager

  • Integration of all firewalls into the FortiManager
  • General administration of the firewalls via the FM
  • Monitoring & Optimization


FortiAuthenticator:

  • General management of users
  • Administration of authentication methods
  • Troubleshooting Faulty HA Clusters
    • General Support Services / Troubleshooting Incidents
    • Regular firmware upgrades (PSIRT checks)
    • Security/Threat Analysis
    • Support for the SD-WAN pilot project

Large international corporation
1 year
2023-03 - 2024-02

Customer project planning of a new network architecture

  • Development of a new network infrastructure
  • Network Design Visio
  • Network segmentation and VLAN concept (BSI compliant)
  • Firewalling Concept
  • Creation of an IPAM
  • Planning Number of Access Points
  • Expense planning for the move
  • Review of procurements
Public Administration
11 months
2023-02 - 2023-12

Further development of the digital workplace of all employees

Further development of the digital workplace of all employees of the State of Berlin in the area of LAN and printers
  • Technical project management
  • Further development of the monitoring and security concept in the area of LAN (reporting via CheckMK, 802.1x-Auth)
  • Conception of location-flexible working in the LAN sector
  • Conception of the comprehensive administrative WLAN
  • Project management Implementation of pull printing in the area of printing (management of print jobs via central print servers, RFID card authentication)
  • Assessment of IT architecture requirements taking into account the eGovernment Act
Public Administration
6 months
2022-09 - 2023-02

Support for IT and redesign of the WLAN Infrastructure

  • Support of the IT department in support
  • Troubleshooting
  • Review of the redesign of the new Extreme WLAN infrastructure (complete replacement of the existing infrastructure, migration to a new controller)
Research Institute
6 months
2022-04 - 2022-09

IP address harmonization

  • Advice on migration procedures:
    • Advice on migrating services to the cloud
    • Review of the existing OBASHIs
    • Advice on migration strategy and corresponding scheduling based on the OBASHIs
  • Advice on address translation (=NAT) as an interim solution for the conversion to IPv6:
    • Parallel to the migration process: Analysis of communication links
    • Classification of communication links for which a NAT is required
    • Recommendation of the appropriate NAT strategy for the respective communication links
  • Review of the customer's network plans for security vulnerabilities
Public Administration
5 months
2021-12 - 2022-04

Support in the area of access LAN of the customer

  • Configuration and Administration of >1200 L2/L3 Devices (Cisco Catalyst 9200, 9300)
  • Construction and commissioning of new data centers for various customers
  • Improvement of customers' NAC infrastructure:
    • Prevention of spoofing attacks
    • Prevention of DoS and DDoS attacks
  • IPAM and Cisco ISE Administration for the ITZ Bund locations
  • Monitoring (Checkmk)
  • Troubleshooting in the area of Access LAN
  • Second/third-level support in the area of access LAN
Public Administration
7 months
2021-06 - 2021-12

Construction, commissioning and administration

Network Administrator
Network Administrator
  • Construction, commissioning and administration of new WLAN and LAN infrastructures (Cisco, Extreme/Aerohive); Support of >300 locations with large infrastructures
  • Network analyses / troubleshooting of performance problems (3rd level)
  • Plan and illuminate new wireless networks with Ekahau Site Survey
  • Management of access points via the cloud controller (Extreme Cloud IQ)
  • Creation of internal documentation (Confluence)
NetCologne IT-Services GmbH

Aus- und Weiterbildung

Aus- und Weiterbildung

2006 - 2007

Vocational training as a technical Communication assistants


2004 - 2005

Vocational College for Technology and Communication

Hohentwiel Vocational School Singen / Vocational College Technology & Media, BSZ Stockach


Key Focus:

  • Basics of network technology
  • Technical communication
  • Basics of programming in Java


Certifications

  • Fortinet NSE 4 FortiGate Administrator (FCP)
  • Fortinet Certified Associate (FCA),
  • Fortinet Certified Fundamentals (FCF),
  • Threat Landscape 2.0 Fortinet,
  • Cybersecurity 2.0 Fortinet,
  • Cisco Certified Network Associate (CCNA),
  • Extreme Wireless Cloud,
  • NAT Cisco Routers,
  • Network analysis with Wireshark

Position

Position

  • Network Security Engineer
  • Network Engineer

Kompetenzen

Kompetenzen

Top-Skills

Fortinet Network Security Cisco Firewall Fortigate IPsec VPN Netzwerkinfrastruktur Remote Trouble Shooting fortianalyzer fortimanager

Produkte / Standards / Erfahrungen / Methoden

IT ? Skills
  • Firewalling (Fortinet FortiGate)
  • FortiADC
  • FortiManager
  • FortiWeb
  • FortiFAC
  • FortiAnalyzer
  • FortiEMS
  • Patching/Network Building
  • Network Design
  •  Network Basics
  • Switching, Cisco (e.g. Catalyst 9200, 9300)
  • Routing, Cisco
  • Wi-Fi
  • NAC
  • Third-level support
  • Troubleshooting
  • General Project Management
  • Experience in the support of large-scale IT projects
  • Experience in the administration of complex infrastructures


Soft - Skills

  • Strong communication skills
  • Independent work
  • Analytical-Conceptual Thinking
  • Comprehension
  • Problem-solving skills
  • Organizational and leadership skills


Tools / Systems

  • ZTNA
  • SD-WAN
  • FortiGate
  • FortiADC
  • FortiWeb
  • FortiAnalyzer
  • FortiManager
  • FortiEMS
  • FortiFAC
  • Cisco Catalyst
  • Cisco ISE
  • IPAM systems
  • Check_mk
  • Ekahau Site Survey
  • Extreme Cloud IQ
  • incident handling via ticket systems (e.g. Jira, BMC-Remedy)
  • Wireshark
  • Nagios
  • MS Visio
  • Confluence
  • GenuGate
  • Python


more experiences

  • Sales
  • Experience as a manager












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