Infrastructure & network – Franz Korbjuhn

Starting point

Infrastructure grows with the company: servers that have run for years, network components from different vendors, Wi-Fi that was never surveyed, cabling without a plan. Much of it works quietly for years. It becomes a problem during outages, growth or security-relevant changes, particularly when nobody knows exactly how the environment is put together any more.

Goal

Infrastructure with a clear architecture: a segmented network, reliable Wi-Fi, servers on a maintainable virtualisation platform, storage and backup to a proper concept, monitoring, and documentation someone else could carry on from.

Typical work

Services

Network design and Wi-Fi

LAN and Wi-Fi planning with coverage surveys, VLAN segmentation, guest Wi-Fi and quality of service for voice and video.
Firewall and VPN

Next-generation firewall, security zones, site-to-site and client VPN for sites and mobile staff.
Servers and virtualisation

Server consolidation on Proxmox, Windows Server and Linux, Active Directory, high availability where needed.
Storage and backup

NAS and storage concepts, backup with verification, restore tests and defined recovery times.
Server room and cabling

Server rack, structured cabling, UPS and coordination with electricians and providers.
Modernisation and migration

Replacing outdated hardware and operating systems, moving services between on-premises and cloud where it makes sense.
Monitoring and documentation

Monitoring of network and servers, network diagrams, IP plans and operational documentation.

Technology

What I work with — and why.

Proven platforms I work with regularly.

UniFi: A network platform for switches, Wi-Fi and gateways with central management, for single and distributed sites.
Proxmox VE: Open-source virtualisation for server workloads and, for many smaller companies, an economical alternative to VMware.
Proxmox Backup Server: Deduplicated, incremental backup of virtual machines with verification.
Sophos Firewall: Next-generation firewall with segmentation, VPN and a link to endpoint protection.
Defguard: Open-source WireGuard VPN with central user management and MFA.
Windows Server & Linux: Active Directory, file services and line-of-business applications where they should stay on-premises.

How it works

How a project usually runs.

01

Analysis

Site walk-through, inventory, survey measurements and requirements.
02

Design

Network diagram, IP plan, hardware selection, schedule and budget.
03

Delivery

Build and migration outside core hours, with testing before go-live.
04

Operation

Monitoring, firmware updates, backup checks and documentation.

Frequent questions

What clients want to know in advance.

Not finding what you want to know? Ask me directly.

01 Proxmox instead of VMware — is that suitable for a business?

Yes. Proxmox is an established virtualisation platform and can be an economically interesting alternative to VMware, especially for small and mid-sized environments. Whether a switch makes sense depends on your applications, availability requirements and support needs.

02 Is UniFi a good fit for our company?

For most small and mid-sized environments, yes. Where there are particular requirements for redundancy or certification, there are better-suited platforms. I settle that during the analysis.

03 Does everything have to go to the cloud?

No. Line-of-business applications, large volumes of data or low-latency requirements often argue for on-premises systems. I assess service by service what makes sense commercially and technically.