DWG № DW-PORTFOLIO-2026 · REV A

host dulantha.weerasekara  ·  edge firewall  ·  state: active

Dulantha
Weerasekara

Senior Infrastructure & Security Engineer · Penetration Tester

Six years securing enterprise networks: FortiGate and Cisco ASA administration, VPN architecture, and segmentation across healthcare, telecom, and managed services — sharpened by certified offensive practice.

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Open to relocation and remote roles · Dubai, UAE

ZONE · PERIMETER seg 10.0.10.0/24

What I run in production

The perimeter is where I have spent six years: policy, tunnels, segments, and the traffic that proves they work.

Firewall administration

fw-cluster-a

Design, implementation, and daily operation of enterprise firewalls: policy management, NAT, least-privilege rulebases, high-availability pairs, and security hardening.

  • FortiGate
  • Cisco ASA
  • Sophos
  • Sangfor
  • Policy optimization
  • NAT

VPN architecture

vpn-hub-01

Site-to-site IPsec and SSL VPN design and operation for secure remote connectivity at enterprise scale.

  • IPsec S2S
  • SSL VPN
  • 100+ remote users

Routing & segmentation

core-sw-01

LAN/WAN routing and switching, VLAN design, and firewall-enforced segmentation that isolates critical systems.

  • Routing & switching
  • VLANs
  • Subnetting
  • DHCP / DNS

Traffic analysis & monitoring

noc-mon-01

Firewall log review, packet-level troubleshooting, and anomaly detection across LAN/WAN environments, plus audits and policy reviews for compliance.

  • Wireshark
  • Firewall logs
  • Security audits
  • Windows Server
  • Linux
  • Active Directory
ZONE · TRUST seg 10.0.20.0/24

Where the uptime happened

Seven years of production networks: healthcare software in Dubai, telecom across the Gulf, managed enterprise services in Sri Lanka.

Nano Health Suite

Senior Infrastructure & Security Engineer Dubai, UAE
03/2026 – present
  • Manage and secure enterprise IT infrastructure and network environments, with a focus on reliability, scalability, and cybersecurity.
  • Implement security controls, access management, and secure connectivity: firewall administration, VPN, endpoint security, and secure remote access.
  • Perform vulnerability assessments, risk mitigation, and security hardening across infrastructure.
  • Monitor, analyze, and respond to infrastructure and security incidents, with root-cause analysis and resolution.
  • Manage backup, disaster recovery, and business-continuity processes.
  • Maintain security policies, compliance standards, audit reports, and operational documentation.

Freelance

Junior Penetration Tester Remote, UAE
01/2025 – present
  • Perform web application, network, and infrastructure security assessments: reconnaissance, vulnerability scanning, and enumeration.
  • Identify security misconfigurations and vulnerabilities; validate security controls and hardening measures.
  • Prepare technical findings and remediation recommendations, following responsible-disclosure and ethical testing practice.

Northtelecom LLC

Network Security Specialist Dubai, UAE
04/2022 – 12/2025
  • Secured and optimized network infrastructure supporting 100+ clients, reducing security incidents by 30%.
  • Managed FortiGate and Cisco ASA firewalls: security policies, NAT, and access control, cutting unauthorized access attempts by 40%.
  • Implemented site-to-site IPsec and SSL VPN for secure remote connectivity (100+ users).
  • Resolved 200+ incidents while maintaining 99.9% uptime across LAN/WAN environments.
  • Configured VLANs, routing (OSPF, EIGRP), and firewall-enforced segmentation to isolate critical systems.
  • Ran vulnerability assessments with Nessus and manual enumeration; analyzed traffic with Wireshark and Nmap.
  • Conducted security audits, device hardening, and least-privilege policy reviews; produced Visio-based security documentation.
  • Also held: Junior Field Engineer (04/2022 – 06/2024) — VSAT and satellite communications fieldwork: Intellian/KNS marine antenna installs, iDirect X7/X5 modems, Mikrotik and Peplink troubleshooting, VoIP configuration, offshore support.

MillenniumIT ESP

Associate Network Engineer Sri Lanka
07/2019 – 04/2022
  • Configured Cisco Catalyst (9500/9300/9200) and Dell N-series switches supporting 200+ users.
  • Conducted Wi-Fi site surveys with Ekahau, improving wireless performance by 40%.
  • Analyzed and optimized firewall rules, strengthening network security posture by 20%.
  • Identified and mitigated vulnerabilities in legacy Cisco devices; ran Cisco health assessments.
  • Conducted traffic analysis with Wireshark and supported backup & disaster-recovery operations.
ZONE · LAB seg 172.16.0.0/24 isolated segment — offensive practice

A defender who studies the attack

Hands-on offensive security in isolated lab environments, because the best firewall policies are written by someone who knows how they get bypassed.

Hack The Box & TryHackMe

Completed the Junior Penetration Tester path; ongoing network and Active Directory exploitation simulations, practicing both offensive and blue-team methodology.

Home lab

Virtual environment on VMware / VirtualBox for testing routing designs, firewall policies, and penetration-testing scenarios end to end.

CTF & red-team exploration

Multiple Capture-the-Flag competitions; forensic investigation and privilege-escalation challenges.

Network automation

Automated secure network deployment in Java (final-year academic project) that cut setup time in half.

toolchain: NmapNessusBurp SuiteMetasploitWiresharkKali Linux
ZONE · CERT AUTHORITY trust anchor

Certificates, issued and verifiable

Every credential below is real and current; the chain of trust verifies on Credly.

Core credentials

certificate store · 8 entries · root of trust
CERTIFICATEISSUERISSUEDSTATE
Certified Penetration Testing Specialist (CPTS)Hack The Box2026valid
ISO/IEC 27001:2022 Lead AuditorMastermind2025valid
PenTest+ (PT0-002)CompTIA2025valid
Network Vulnerability Assessment Professional (CNVP)CompTIA2025valid
Security+ (SY0-701)CompTIA2024valid
NSE 1 · 2 · 3 — Network Security AssociateFortinet2023valid
Certified Specialist — Enterprise Core (CCNP)Cisco2021valid
CCNACisco2021valid

Continuing learning

supplementary store · 4 entries
CERTIFICATEISSUERISSUEDSTATE
Introduction to Critical Infrastructure Protection (ICIP)OPSWAT2026valid
Jr Penetration Tester CertificateTryHackMe2025valid
Web Fundamentals CertificateTryHackMe2024valid
Peplink Certified EngineerPeplink2024expired 2026

Verify the chain: credly.com/users/dulantha-weerasekara

Education

  • BSc (Hons) Computer Science — Networking & Network Security, Kingston University, UK · First Class Honours2020–2021
  • Pearson BTEC HND in Computing — Network Engineering, Esoft Metro Campus, Sri Lanka · Distinction2018–2020
  • Pearson BTEC HND in Computing — Software Engineering, Esoft Metro Campus, Sri Lanka · Distinction2018–2020
  • Diploma in Software Engineering, Java Institute, Sri Lanka2016–2018
ZONE · MANAGEMENT out-of-band

Open a session

Hiring for network security, infrastructure security, or a defender who understands offense? The management interface is up.

Download CV (PDF)

Dubai, UAE · open to relocation & remote