David Smith
F5 Networks Engineer · Dallas, TX
The engineer you call when the project is complex and the margin for error is zero.
Summary
Twenty-plus years in the infrastructure trenches — nine of them running application delivery at a managed-hosting provider, then Professional Services out in customer environments. I run F5 BIG-IP from the CLI and Wireshark from muscle memory. I read packets before I read ticket titles. Small-shop generalist roots, enterprise-scale F5 instincts.
Trading as LabSmith.net for consulting engagements — F5 BIG-IP implementations, hardware and version migrations, TLS migrations, iRules work, and the kind of load-balancer troubleshooting that needs someone who can draw the handshake on a whiteboard and then confirm it on the wire.
Technical Skills
Application Delivery & Load Balancing
- F5 BIG-IP LTM
- BIG-IP DNS (GTM)
- iRules
- Server & Client SSL profiles
- SSL offload
- Health monitors (bigd & In-TMM)
- Brocade ADX (legacy)
Networking & Security
- TLS 1.0 – 1.3, SNI, cipher suites
- HTTP/1.1, HTTP/2
- DNS
- Cisco ASA
- TCP/IP fundamentals
Operating Systems & Scripting
- Linux (Ubuntu, Debian, RHEL family)
- Bash
- Python
- PowerShell
- Windows Server administration
Tooling & Observability
- Wireshark / tshark
- tcpdump
- SSLKEYLOGFILE decryption
- KVM
- GNS3
- Docker
Professional Experience
- Deep-dive lab on TLS 1.3 health monitor behavior and In-TMM monitoring — full NGINX + BIG-IP VE topology in GNS3 with strict SNI enforcement.
- Published "A TLS 1.3 Question That Probably Cost Me a Job" — practitioner walkthrough with tshark before/after and F5 KB references.
- Scaffolded LabSmith.net consulting presence — brand, proposal templates, CRM-style client pipeline.
- F5 BIG-IP Professional Services delivery across enterprise customer environments — implementations, upgrades, and remediation on live load-balancing infrastructure.
- Hardware and platform migrations — iSeries and rSeries refreshes, VIPRION decommissions, and Viprion-to-rSeries cutovers with HA sync, cert migration, and iRule compatibility checks through the transition.
- Version upgrades across v13 → v15 → v17 — TMOS pre-flight qkview analysis, cipher/TLS change audits, scripted rollback plans, and cutover during customer change windows.
- Config migrations between appliances and virtual editions — UCS-driven moves where sensible, bigip.conf surgery where not.
- Application delivery lead across a multi-tenant managed-hosting platform — F5 BIG-IP (LTM) alongside Brocade ADX.
- iRules development for header manipulation, traffic steering, and session persistence problems that plain profiles could not solve.
- SSL offload at scale — profile design, cipher selection, and cert lifecycle across the fleet.
- Packet-level troubleshooting with Wireshark / tcpdump on everything from TCP handshake failures to TLS alert storms.
- Recognized as go-to application-delivery resource; mentored junior engineers into production-ready on-call rotation.
- Network and security operations — firewall administration, VPN connectivity, and IDS/IPS tuning for enterprise customers.
- Owned the full IT stack for the police-radar manufacturer over 11 years — systems, networking, and security for a small shop with a broad scope.
- Cisco ASA firewalls, Exchange, DNS, web, and database hosting — end-to-end ownership from hardware up through application layer.
- The memorable one: yes, the radar-gun company. Small enough to touch everything. Big enough to matter.
- Desktop and application support at the telecom scale — where "learning to troubleshoot under pressure" was the actual job description.
Certifications
Active
- F5 Certified Administrator, BIG-IP (F5-CA)
- F5 Certified Technical Specialist, BIG-IP DNS (F5-CTS)
Prior & Lapsed
Listed because the knowledge didn't lapse with the paper. Security fundamentals from CISSP, cloud fluency from AWS, and the routing/switching base from the Cisco and CompTIA tracks all inform how I approach every engagement.
- CISSP (ISC2) 2013 – 2016
- AWS Certified Solutions Architect – Associate 2019 – 2022
- CCNA expired
- CCNA Security expired
- CompTIA Security+ expired
- CompTIA Network+ expired
Education & Training
- Southern Methodist University — MCSE Program (1999), MSDBA Program (2000) — School of Engineering and Applied Science
- Collin County Community College — Unix Administration
- Alamo Colleges District — Wireshark Packet Analysis
- CCNP Switch — Coursework
- Ethical Hacking — CEH preparation
Recent Writing
Published walkthroughs from the lab — packet captures, configs, the side-quest corrections.
Read the articles →