Raspberry Pi and Banana Pi Infrastructure Planning

Why This Note Exists

This note documents the decision-making process behind choosing small ARM hardware for network infrastructure.

The goal was not only to compare boards by CPU, RAM, or price. The real question was:

Which device makes sense as a reliable router, VPN endpoint, VLAN gateway, or small infrastructure controller?

The hardware options included Raspberry Pi and Banana Pi devices, especially in the context of:

OpenWrt routing
VLAN separation
managed switch setups
VPN access
homelab isolation
small business/server infrastructure
low-power always-on operation
avoiding overcomplicated hardware choices

This note is about infrastructure planning, not gadget collecting.

Project Context

The environment involved a home and small-lab network where the router was more than a basic ISP box.

The network direction included:

OpenWrt as the main control layer
VLAN-based separation
VPN access
DNS filtering
self-hosting experiments
Proxmox/homelab services
game server hosting experience
future small-business infrastructure planning

The key devices considered were:

Raspberry Pi 5
Banana Pi BPI-R4 family
Banana Pi BPI-R4 Lite direction
managed switches
mini PCs for heavier server workloads

The important design decision was whether the board should act mainly as a router, a service host, or a support device.

What This Planning Is Meant To Prove

hardware choice should follow network design
a board with one Ethernet port can still route VLANs with the right switch
router-on-a-stick works, but it has tradeoffs
router-native boards are cleaner for multi-port routing
VPN, VLANs, DNS, and firewalling should be planned together
storage and reliability matter for always-on infrastructure
support/community can matter more than raw specs
not every workload belongs on the router

Stack and Tools Considered

Hardware Layer

Raspberry Pi
Banana Pi
ARM boards
managed switches
SD cards
eMMC/NVMe direction
power supply quality
cooling
Ethernet/SFP interfaces

Service Layer

AdGuard Home
WireGuard
DDNS updater
small bots/scripts
monitoring direction
homelab access control
server management

Intended Build

The intended infrastructure direction is a small, low-power network stack that can support:

internet routing
VLAN separation
VPN access
DNS filtering
isolated homelab/server network
safe remote administration
future expansion
clear separation between router duties and heavier server duties

A finished design should answer:

What device routes traffic?
What device switches VLANs?
Where does VPN terminate?
Where do services run?
Where are sensitive systems placed?
What happens if one device fails?

Raspberry Pi as OpenWrt Router

A Raspberry Pi can work as an OpenWrt router, especially when paired with a managed switch.

The typical limitation is Ethernet.

A Raspberry Pi with one Ethernet port can use a router-on-a-stick design:

ISP/ONT
  ↓
managed switch
  ↓ tagged VLAN trunk
Raspberry Pi running OpenWrt
  ↓ tagged VLAN trunk
managed switch
  ↓
LAN / homelab / server VLANs

This can work well when VLANs are configured correctly.

The managed switch becomes essential because traffic for WAN and LAN zones is separated using VLAN tags over the same physical interface.

Router-on-a-Stick Direction

Router-on-a-stick means one physical network interface carries multiple VLANs.

Example direction:

eth0.10 → Home LAN
eth0.20 → Homelab LAN
eth0.1141 → WAN / ISP VLAN direction

This design can be practical, but it depends on:

correct VLAN tagging
managed switch support
clear port profiles
OpenWrt interface setup
firewall zone separation
avoiding accidental untagged traffic mistakes

The advantage is using one-board hardware effectively.

The disadvantage is that the switch and VLAN config become critical.

Managed Switch Role

A managed switch is not optional in a VLAN-based router-on-a-stick setup.

The switch handles:

tagged trunk port to router
untagged access ports for normal devices
VLAN separation between networks
WAN handoff if needed
homelab/server isolation

Example switch direction:

Port 1 → router trunk
Port 2 → ISP/ONT WAN VLAN
Port 3 → home LAN untagged
Port 4 → homelab VLAN untagged
Port 5 → server/proxmox VLAN untagged

The exact port layout depends on the network, but the principle is the same.

Banana Pi as Router Hardware

Banana Pi router-focused boards can be more natural for OpenWrt routing because they often target networking use cases more directly than a general Raspberry Pi.

The appeal is:

more router-like hardware direction
multiple Ethernet interfaces depending on model
SFP/SFP+ direction on some boards
better fit for WAN/LAN separation
less dependence on router-on-a-stick tricks
room for expansion depending on model

This can make Banana Pi boards cleaner for a serious router role.

But they also require caution:

check OpenWrt support status
check driver maturity
check community documentation
check power/cooling
check availability and price
check exact board revision
check whether the specific model matches the needed ports

A strong board on paper is not useful if support is unstable or documentation is weak.

Banana Pi BPI-R4 Direction

The BPI-R4 direction made sense as a more router-native choice.

It is more aligned with:

OpenWrt router use
multi-port networking
SFP direction
homelab gateway role
centralized network control
future expansion

For a setup that may eventually handle VLANs, VPN, internal services, and more structured routing, a router-focused Banana Pi board can be easier to justify than forcing everything through a single Ethernet port.

The main planning rule:

Use Raspberry Pi when flexibility and availability matter.
Use Banana Pi router boards when network interfaces and router role matter more.

Banana Pi BPI-R4 Lite Direction

The Lite direction can make sense when the full board is unavailable or too expensive.

But “Lite” should not only be judged by price.

The questions are:

does it have the ports needed?
does it support the intended OpenWrt version?
does it support the needed WAN handoff?
does it support the planned storage?
does it support the required throughput?
does it have enough RAM?
does the community use it successfully?
are there known driver issues?

For a startup or early build, using the Lite board can be reasonable if the requirements are clear and the missing features are not needed.

Raspberry Pi vs Banana Pi Decision

A simple comparison:

Area	Raspberry Pi Direction	Banana Pi Router Direction
Best role	flexible small server/router	router-focused gateway
Ethernet	often limited	usually stronger networking focus
VLAN routing	possible with managed switch	often cleaner with more interfaces
Community	very strong general community	more specialized
OpenWrt use	workable	often targeted, but check support
Availability	often easier depending on market	can be harder locally
Expansion	depends on model/HATs/adapters	depends on board design
Risk	USB/Ethernet/workaround complexity	support/documentation maturity
Best use	lab, VPN, DNS, small services	central router/gateway

The best choice depends on the role.

Router vs Server Separation

One important decision is not to overload the router.

A router should prioritize:

routing
firewall
VLANs
DHCP
DNS
VPN
DDNS
light monitoring

Heavier workloads should move to:

mini PC
Proxmox server
VPS
dedicated service host

Examples of workloads that may not belong on the router long-term:

heavy databases
large Docker stacks
game servers
media servers
CI/build processes
large file storage
public web apps with heavy traffic

A router can run small scripts, but it should remain stable first.

Mini PC Role

A mini PC can complement the router.

Better split:

OpenWrt router:
  routing, firewall, VLAN, VPN, DNS

Mini PC / Proxmox:
  applications, databases, dashboards, containers, automation

This keeps the network layer reliable while allowing services to grow separately.

For small-business infrastructure, this split is cleaner than using one board for everything.

VLAN Planning

The infrastructure design should separate traffic by purpose.

Example VLAN direction:

Home VLAN
Admin VLAN
Homelab/Server VLAN
Guest/IoT VLAN
DMZ if public-facing services exist

The exact design should stay simple at first.

Too many VLANs create management overhead.

A practical early structure:

Home
Homelab/Servers
Guest/IoT
Admin/VPN

The goal is to prevent everything from living in one flat network.

VPN Placement

WireGuard can run on the router or a separate host.

VPN on Router

Advantages:

direct access control at network edge
simple routing to VLANs
fewer devices
good for admin access

Risks:

router workload increases
mistakes can affect network access
backup/recovery matters

VPN on Separate Host

Advantages:

services separated from router
easier to rebuild or containerize
can sit in DMZ/access layer

Risks:

routing/firewall rules need more care
more moving parts
port forwarding may be needed

For small/home infrastructure, VPN on OpenWrt is often practical.

For bigger setups, a dedicated VPN/access gateway can be cleaner.

DMZ Direction

A DMZ can be useful when hosting public-facing or semi-public entry services.

A clean model:

Internet
  ↓
Router/firewall
  ↓
DMZ / access layer
  ↓
Private internal services

Public-facing services or controlled gateways can sit closer to the edge.

Sensitive services, databases, and admin panels should remain in private networks.

The hardware decision should support this design through VLANs and firewall rules.

Storage Considerations

Always-on router boards often use SD cards, eMMC, or NVMe depending on model.

Storage matters because:

logs write over time
packages need space
Docker can consume space
databases write constantly
sudden power loss can corrupt storage
SD card quality varies

For a router:

stable storage > large storage

For servers:

SSD/NVMe preferred

Do not run write-heavy services on weak SD cards if reliability matters.

Power and Cooling

Small boards are sensitive to bad power and heat.

Planning should include:

quality power supply
stable voltage
cooling/heatsink
airflow
safe enclosure
UPS direction if important
avoiding cheap cables/adapters

Unstable power can look like software failure.

Random crashes, filesystem corruption, and network drops can all come from power/cooling problems.

Throughput Considerations

Router hardware should be chosen based on expected traffic.

Questions:

internet speed
WireGuard speed needed
inter-VLAN routing load
SQM/QoS need
number of clients
number of firewall rules
IDS/monitoring plans
public services or only private access

A board that is fine for basic routing may struggle with heavy VPN encryption, SQM, or high inter-VLAN traffic.

Availability and Repairability

A technically perfect board is less useful if it is impossible to replace.

Practical buying questions:

can the board be bought locally or regionally?
can the power supply be replaced easily?
are cases/heatsinks available?
are spare SD/eMMC/storage options available?
is documentation available?
do other users run OpenWrt on it successfully?
can the setup be restored onto another device?

For client or business-facing infrastructure, availability matters.

Documentation Direction

Infrastructure hardware decisions should be documented clearly.

Useful documentation:

network diagram
VLAN table
port map
device role list
IP plan
firewall zone summary
VPN access notes
backup/recovery note
hardware list
why this board was chosen
what this board should not do

This makes the setup maintainable later.

Practical Decision Tree

Need simple OpenWrt router and already have managed switch?
  → Raspberry Pi can work with router-on-a-stick.

Need cleaner router hardware with more network interfaces?
  → Banana Pi router-focused board is stronger.

Need to run heavier services?
  → Use mini PC/Proxmox, not the router board.

Need public/self-hosted services?
  → Consider DMZ/VLAN design and maybe VPS.

Need only VPN + DNS + firewall?
  → Keep router simple and stable.

Practical Decisions

Do not choose hardware only by specs

Support, documentation, and replacement availability matter.

Router should stay boring

The router should be stable before it is clever.

Separate heavy services

Use the router for network control and a mini PC/server for applications.

Use VLANs deliberately

VLANs should solve real separation needs, not create confusion.

Plan for recovery

If the router board dies, the network should be recoverable from documentation and backups.

Check support before buying

Especially for Banana Pi/router-focused boards, verify the exact board revision and OpenWrt support direction before committing.

What A Finished Plan Should Show

A strong infrastructure plan should show:

selected router device
reason for choosing it
WAN/LAN/VLAN design
managed switch port map
VPN placement
DNS filtering placement
server/homelab separation
storage choice
cooling/power choice
backup/recovery direction
what services run where
what is intentionally not exposed

Evidence Worth Capturing

Useful evidence for this note would include:

hardware photos
OpenWrt dashboard screenshot
VLAN interface list
switch VLAN configuration screenshot
network diagram
WireGuard status
DNS filtering status
storage usage
port map table
mini PC/router role split
before/after topology comparison

Technical Assumptions

This note assumes the infrastructure is for a home lab, small network, or small-business style environment.

It assumes OpenWrt is used as the routing/firewall layer.

It assumes the hardware choice must balance cost, availability, support, ports, and future expansion.

It also assumes that not every service should run on the router itself.

Key Risks

relying on router-on-a-stick without understanding VLAN tagging
choosing a board with weak OpenWrt support
overloading the router with heavy services
using bad power supplies
running write-heavy services on weak SD cards
buying hardware based only on theoretical specs
creating too many VLANs too early
no port map documentation
no backup of OpenWrt config
exposing admin services instead of using VPN
choosing unavailable hardware for a client-facing setup

Current State

This note represents the hardware and infrastructure planning direction behind choosing Raspberry Pi or Banana Pi devices for OpenWrt and small-network deployments.

The strongest value is the decision framework:

router role
switch role
server role
VPN role
VLAN design
storage/reliability
support/availability

That is more useful than a simple “which board is better” comparison.

What This Note Does Not Claim

This note does not claim one board is always better.

It does not claim Raspberry Pi is a perfect router.

It does not claim Banana Pi is automatically production-ready without checking support.

It documents practical infrastructure planning around small ARM boards, OpenWrt, VLANs, VPN access, and homelab/small-business network design.

Practical Takeaway

The useful lesson is:

Choose the hardware based on the network role, not the product name.

A clean setup separates responsibilities:

router → routing, firewall, VPN, DNS
switch → VLAN access/trunks
server/mini PC → applications and heavy services
DMZ/private networks → exposure boundaries

That makes the infrastructure easier to understand, expand, and recover.