Skip to content

ADR: Rack UPS and Network Switch Selection

Home / Infrastructure / Rack UPS and Network Switch Selection

Status: Accepted

Context

We are building out a server rack that will contain rackmounted compute systems, UPS units, and supporting network equipment. We wanted components that fit standard server rack dimensions, support near-term growth, and are manageable by a small team that may not include deep networking specialists.

For the network layer, we also wanted something more controllable and debuggable than a basic unmanaged switch, ideally with a real CLI so configuration and troubleshooting can be assisted or automated through tools like Claude.

Decision

We selected:

  • UPS: Eaton 5PX G2 rackmount UPS
  • Switch: MikroTik CRS312-4C+8XG-RM

Main reasons

1. Rack-native hardware

Both devices are designed for standard 19-inch rack deployment, which keeps the build clean and avoids mixing desktop-style equipment into the rack.

The MikroTik CRS312-4C+8XG-RM is a 1U rackmount switch and MikroTik states that it fits standard racks. The Eaton 5PX G2 line is also built for rack installation, with the selected 2U models sized for standard server racks.

2. Room to grow

The MikroTik switch gives us meaningful headroom without immediately overbuilding.

It provides:

  • 8 fixed 10Gb RJ45 copper ports
  • 4 combo 10Gb ports that can operate as RJ45 or SFP+
  • 120 Gbps non-blocking throughput
  • 240 Gbps switching capacity

This gives us enough ports for the current machines plus upstream network/storage connections, while still leaving room for additional systems later.

3. Better manageability than an unmanaged switch

We deliberately chose the MikroTik instead of a simpler unmanaged switch because unmanaged switches are easy to plug in, but much harder to inspect, troubleshoot, and automate once the rack gets more complex.

The MikroTik supports RouterOS and SwOS, includes a console port, and in RouterOS mode supports CLI-based administration and scripting. That gives us much better visibility and control than an unmanaged switch, including the ability to inspect ports, export configuration, and apply repeatable scripted changes.

4. Compatible with AI-assisted administration

A major advantage of the MikroTik is that it has a real management surface that can be driven through CLI-style workflows. That makes it a better fit for administration through Claude or other automation than browser-only switches.

This does not mean it is unmanaged. It is the opposite: it is a managed switch with significantly more control and debuggability than an unmanaged model. In practice, that gives us better operational leverage even if networking expertise on the team is limited.

5. Optional fiber experimentation later

The MikroTik is mostly copper-oriented, which is convenient for ordinary workstation connections today, but it also includes SFP+ capability through the combo ports.

That gives us a path to experiment later with:

  • fiber uplinks
  • DAC cables
  • different storage/uplink topologies

without forcing the entire rack into an all-fiber design now.

6. UPS supports current needs with expansion path

The Eaton 5PX G2 was selected because it is a proper rack UPS with enough capability for the current build and a clean upgrade path for future needs.

Eaton documents support for:

  • rack deployment
  • optional network management via Network-M3
  • external battery expansion on supported models

This gives us a solid UPS now while leaving room for better monitoring and longer runtime later if the rack grows.

Alternatives considered

QNAP QSW-M3216R-8S8T

Strong rackmount 10Gb option with good port density and web-based management, but not ideal for our use because it is primarily browser-managed and does not provide the kind of end-user SSH/CLI workflow we wanted for automation and Claude-assisted administration.

Attractive low-cost 10Gb option and very easy to deploy, but it is unmanaged, which limits visibility, debugging, and long-term flexibility. It would be reasonable only if we were intentionally treating the switch as temporary infrastructure.

Consequences

Benefits

  • Clean rack-native deployment
  • Enough 10Gb copper capacity for current systems and moderate growth
  • Some SFP+ flexibility for future experimentation
  • Better debugging and operational control than unmanaged gear
  • CLI/API-friendly administration path for automation and AI-assisted workflows
  • UPS platform with network management and battery expansion options

Tradeoffs

  • More setup complexity than an unmanaged switch
  • MikroTik administration is more powerful, but requires some care and discipline
  • The switch has fewer total ports than the QNAP, though it better matches the CLI/automation requirement
  • SFP+ support is partial rather than a full all-fiber design

Summary

We chose the Eaton 5PX G2 and MikroTik CRS312-4C+8XG-RM because they give us a rack-native, expandable, and operationally manageable foundation. The Eaton provides a proper rack UPS with future management and runtime expansion options, and the MikroTik provides a 10Gb switch with enough copper for today, some SFP+ flexibility for tomorrow, and a real CLI-based management model that is better suited to automation and troubleshooting than an unmanaged or browser-only alternative.