Serial over LAN solutions

Serial over LAN Software and Hardware Solutions

Updated: Aug 4, 2026

Tested by Nikolai Svarachevsky, Lead Developer with 20+ years working on COM port virtualization.
Written by Robert Agar, Former IBM Technical Writer with 13 years of experience.

Your serial device is wired into one machine. The software that needs it now runs somewhere else, another floor, another building, the cloud. Serial over LAN closes that gap, making a serial port on one computer usable from another over the network.

Five ways to do this: two software tools, two hardware adapters, an embedded component for OEMs, and free Linux commands that need no install. We compare price, setup effort, and protocol support for each.

Note: How We Tested This
Our Lead Developer, Nikolai Svarachevsky, personally tested cloud access with both Serial to Ethernet Connector and FlexiHub using the same hardware and comparable network conditions. This allowed us to compare their connection methods without introducing unrelated variables.

In addition to hands-on testing, Nikolai verified supported interfaces, connection modes, required drivers, protocol support, and port count against the hardware listed below. This comparison does not evaluate performance, speed, or reliability, as those require dedicated benchmarking.

Best Serial over LAN Solutions

Application

How we tested this:

Serial to Ethernet Connector connects two computers directly over TCP, without a vendor relay. The computer sharing the serial device needs to be reachable on the network, whether via LAN, a public IP, port forwarding, or a VPN.

The Zebra DS2208 scanner was connected via its RS-232 interface through a StarTech ICUSB2321F USB-to-RS232 adapter to a Windows 11 workstation, appearing as a physical COM port. A Server connection was set up on this workstation: in SEC, the Server role belongs to whichever machine holds the physical device, so it's this machine that must be reachable, not the client. Port forwarding was configured on the local router for SEC's TCP port to make that possible.
An AWS EC2 t3.small instance (Windows Server 2022) was set up with a Client connection pointed at the workstation's public IP and forwarded port, creating a virtual COM port linked to the scanner. A cloud-based inventory app on the EC2 instance read barcode data through that virtual port.
An operator at the workstation scanned test barcodes with the Zebra DS2208. From a separate Windows 11 laptop, a second person checked the inventory app's dashboard on EC2 and confirmed each scan appeared correctly in real time.

Software version tested: Serial to Ethernet Connector 9.0.1288.

Operating systems: Windows 11 Pro 24H2 (host), Windows Server 2022 Standard (AWS EC2), Windows 11 Pro 24H2 (client).

Serial to Ethernet Connector

Serial to Ethernet Connector (SEC) turns any serial device connected to one PC into something you can use from another, as if it were plugged in right next to you. The app doesn't touch the underlying protocol; it just tunnels the existing serial connection over the network, so RS-232, RS-422, and RS-485 hardware all work the same way. You can reach a shared device through a virtual COM port, a plain TCP connection, or RFC 2217 if your software already speaks that. Works fine on a local network, and over the internet too, as long as the server has a public IP or the two machines can otherwise see each other.

The basic setup is one machine sharing a port, another connecting to it as a virtual COM port. But SEC can do more than that if you need it to: share several devices off one computer, let multiple clients hit the same device, expose a port over raw TCP so the client doesn't even need SEC installed, or broadcast to several listeners at once over UDP.

There's also a set of advanced settings for older or fussier serial gear: packet delay, message length limits, trigger characters, that sort of thing. And since it supports raw TCP, UDP, and RFC 2217, you're not locked into a proprietary driver on the client side.

Pros:

Share as many real or virtual serial ports as you want, from one machine
Fine-grained port settings for tricky legacy hardware
Can spin up virtual ports even with no physical COM port present
Handles multi-client and multi-server setups
One license covers both server and client roles
Open standards (RFC 2217, raw TCP/UDP), no vendor driver required
Hardware control signals (RTS/CTS, DTR/DSR) are supported

Cons:

You need a host machine actually running SEC; no talking to bare hardware directly
Windows and Linux only, nothing else
Needs a public IP on the server, or both machines on the same LAN
Setting it up over the internet takes more work than a relay-based tool would

Price: $260, one-time purchase license. 14-day free trial available.

Note: SEC vs. FlexiHub: the real difference. If your server sits behind a router without a public IP, a common situation for home or small-office setups, FlexiHub will connect out of the box, while SEC requires either a public IP address or both machines being on the same local network. If you already control your network infrastructure and need multiple simultaneous connections or virtual port hosting, SEC's direct-connection model gives you more flexibility; if you don't have a public IP or want zero network configuration, FlexiHub's relay model is the simpler path.

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Application

How we tested this:

FlexiHub doesn't require a direct connection. It uses one when possible and falls back to its own relay servers when not, without needing port forwarding, a public IP, or manual network setup on either end.

FlexiHub was installed on a Windows 11 workstation with the Zebra DS2208 connected via its RS-232 interface through the same StarTech ICUSB2321F adapter used in the SEC test.
The scanner's port was shared through FlexiHub, making it visible to other devices signed into the same account rather than through a direct network address.
An operator at the workstation scanned test barcodes. From a second Windows 11 laptop, we signed into the same FlexiHub account, connected to the shared device remotely, and confirmed each scan was received correctly.

Software version tested: FlexiHub 6.0.

Operating systems: Windows 11 Pro 24H2 (host), Windows 11 Pro 24H2 (client).

FlexiHub

FlexiHub is built around a simpler scenario than SEC: one computer shares a device, one other computer connects to it. There's nothing here matching SEC's multi-device or broadcast setups. It still works with whatever physical standard the host's port already uses (RS-232, RS-422, or RS-485), since like SEC it shares the existing port rather than converting the signal. Where FlexiHub earns its keep is convenience: it handles all the routing itself, so it works over the internet right out of the box, no public IP and no network setup on either side. The catch is that both computers need FlexiHub installed and signed into the same account, and unlike SEC, it won't talk to a plain TCP client on the other end.

As long as you're online, you can see and connect to any serial device plugged into a machine running FlexiHub under your account.

Pros:

Works over the internet with no hosting or port forwarding needed
No public IP required; it relays through FlexiHub's cloud, so it works behind NAT and routers
Port emulation on the client side
50 connections on the entry plan, up to 1000 on higher tiers
Cross-platform: Windows, macOS, Linux, mobile

Cons:

Requires an active subscription
Needs FlexiHub on both ends; unlike SEC, it can't connect via a plain TCP client
No broadcast (UDP) or multi-server modes, unlike SEC
Only shares an existing physical or virtual serial port. Unlike SEC, it can't create standalone virtual COM ports for custom connection scenarios
Over a multi-year deployment, the subscription ends up costing more than SEC's one-time license

Price: from $39.99/month (Personal, 50 connections).

Business Starter is $79.99/month (300 connections, up to 5 team members);

Business Plus is $129.99/month (1000 connections, up to 10 team members).

A 30-day demo account is available once per user, limited to 5 remote devices.

Note: SEC vs. FlexiHub: the real difference. If your server sits behind a router without a public IP, a common situation for home or small-office setups, FlexiHub will connect out of the box, while SEC requires either a public IP address or both machines being on the same local network. If you already control your network infrastructure and need multiple simultaneous connections or virtual port hosting, SEC's direct-connection model gives you more flexibility; if you don't have a public IP or want zero network configuration, FlexiHub's relay model is the simpler path.

Adapter

Moxa NPort

NPort 5100 Series devices are single-port serial-to-Ethernet adapters. Depending on the model, the port supports RS-232, RS-422, or RS-485, these are physical standards rather than protocols, and some models support more than one, or all three. The NPort 5100 units also include an adjustable pull high/low resistor for RS-485 lines.

The adapter can be configured over Telnet, in its web interface, or with a Windows or Linux utility.

Out of the box, the device is reachable through raw network modes, TCP Server, TCP Client, UDP, Pair Connection, or Ethernet Modem. To make the port appear as a virtual COM port on the client instead, you need Moxa's own driver: Real COM on Windows, or the TTY driver on Linux and macOS. This is worth knowing before you buy, because it applies on every platform, not just Linux, and it's a vendor-specific driver rather than an open standard.

Pros:

No host computer needed, puts the device on the network by itself
Supports RS-422/RS-485, unlike most built-in PC serial ports
Rugged hardware, 5-year warranty
Adjustable termination and pull high/low resistors for RS-485

Cons:

More involved to configure than installing an application
Needs Moxa's own driver (Real COM/TTY) for virtual COM port use: otherwise limited to raw TCP/UDP
1 port per unit: scaling means buying more hardware, unlike a software solution
No broadcast mode for multiple listeners

Price: Price: from around $215 for the NPort 5150 (the RS-232/422/485 model), or about $177 for the RS-232-only NPort 5110. Prices vary by reseller, roughly $215 at Neteon, $245 at DigiKey, $274 at RS Components.

Driver and OS support: Moxa NPort 5100 Series datasheet

Adapter

The IOLAN Device Server

The DG1 has a single port with a software-selectable RS-232/422/485 interface (again, physical standards rather than protocols). By default it's configured for RS-232; switching to RS-422 or RS-485 is done in software rather than with jumpers. The connected device can be shared to multiple TCP or UDP servers.

As with the NPort, the port is reachable as a raw TCP or UDP connection out of the box. Perle's TruePort software is what turns it into a genuine remote COM port on the client side, so the same "extra software for virtual port" caveat applies here too.

Perle's own marketing describes the IOLAN line as having "powerful processors for the best throughput and performance on the market", that's a vendor claim, and one we have not independently benchmarked.

Perle also offers an IOLAN SDK with tools for process automation, data storage, and logging.

Pros:

No host computer needed
Software-selectable RS-232/422/485, no hardware reconfiguration to switch standards
Can share one serial port with multiple TCP or UDP servers
IOLAN SDK available for automation and logging
IPv6 support and 15kV ESD protection
An extended-temperature model (−40 °C to +74 °C) is available for harsh environments

Cons:

Most expensive option here by a wide margin
Needs TruePort software for true remote COM port access
1 port per unit, vs. unlimited ports on a single machine with software solutions

Price: $596 for the DG1 TX (extended-temperature, part 04031790) or $454 for the standard DG1 DB9 (part 04031774), direct from Perle. (Perle store — DG1 TX · DG1 DB9 · Product page)

Component

Anybus by HMS Networks

As an embedded module, the CompactCom 40 Brick is fundamentally different from everything else here. It isn't a finished product you plug in and use, it's a component for hardware manufacturers who want to build network connectivity into their own device. You add your own connectors (DSUB, RJ45, M12) and network isolation, which is exactly what makes it attractive if you're designing hardware, and irrelevant if you just need to get a printer on the network.

It's built on HMS's NP40 network processor and offers 8/16-bit parallel or high-speed SPI application interfaces, plus I/O via a shift register interface.

Pros:

Compact, fully embeddable in your own product
Choose your own physical connector interface
Can be installed/swapped late in manufacturing
Pre-certified for network compliance, faster certification
HMS maintains the module across its lifecycle

Cons:

Not standalone, needs surrounding hardware you design yourself
Aimed at OEMs, not end users
Significant per-unit cost despite being only one component
No public pricing, only available through distributors

Price: around €182 net per unit through distributors. HMS does not publish public end-user pricing for this component, the figure depends on volume, region, and channel partner. (HMS product page · Elmark, distributor listing)

Note: the CompactCom 40 range includes several application interface variants. If UART is a requirement for your design, confirm it against the datasheet for the exact part number you're ordering, the interfaces differ between models in this family.

Comparison chart

Serial to Ethernet Connector

FlexiHub

Moxa NPort 5150

Perle IOLAN DG1

Anybus 40 Brick

Type

Application

Hardware adapter

Embedded component

Price

$260 one-time

From $39.99/mo

~$215–274

$454–596

~€182 net, distributor

Host computer needed

Yes

No

N/A

Public IP required

Yes, unless same LAN

No — cloud relay

No

N/A

Connections

Unlimited per machine

50–1000 per plan

1 port

1 module

Physical standards

RS-232/422/485 (per host port)

RS-232/422/485 (model-dependent)

RS-232/422/485 (software-selectable)

Configurable (parallel/SPI)

Virtual COM port

Built in, no driver

Built in

Needs Real COM/TTY driver

Needs TruePort

N/A

Connection methods

RFC 2217, TCP, UDP

Proprietary relay

Raw TCP/UDP

Fieldbus protocols

OS support

Win 10/11, Server 2016–2022, Linux (x86+ARM)

Windows, macOS, Linux, mobile

Windows, Linux, macOS drivers

Windows, Linux drivers

N/A

Common usage scenario of Serial over LAN software

After migrating your software to the cloud, you may have issues connecting remotely to your serial-based equipment. You need to implement Serial over LAN functionality so peripherals attached to your serial ports are accessed through the cloud environment. Serial to Ethernet Connector provides the capability to establish COM over LAN connectivity.

Learn about Serial over LAN software and how you can use it in cloud infrastructure

Once correctly configured, this Serial over LAN software solution redirects the COM interface to the cloud. You can now access equipment attached to this port from anywhere with an Internet connection.

How to redirect a COM over LAN using this advanced software solution

Let’s imagine that you have a COM-based barcode reader which is located at a distance from your local computer. You need to access the device from an app installed on your machine. To achieve this, you should follow these simple steps:

1

Download Serial over Ethernet Connector and install it on the computer (server) to which the device is attached physically and your local computer (client) that will reach the serial over LAN. Note that a client can be any real or virtual machine running Windows or Linux OS.

2

Next, start the program on the server machine, set up the required parameters and create a Server connection by clicking the corresponding button. This will make the serial port device accessible over the network.

3

Then, launch the software on the client and “Connect” to the serial port over network.

This is it! Now, all data from the remote COM device will be available on your computer as if it were your local peripheral.

Securing a serial-over-LAN connection

Putting a serial device on a network means it's reachable by anything else that can reach that port. Worth thinking about before you deploy, not after:

• Never expose a raw TCP serial port directly to the public Internet. If you're using a direct TCP solution, protect it with a VPN, SSH tunnel, or another secure transport.

• Restrict access with firewall rules so only authorized systems can reach the shared serial port.

• Review the security features provided by your software. Serial to Ethernet Connector supports password authentication and encrypted connections, while FlexiHub encrypts traffic automatically through its cloud service. Basic tools such as netcat or socat provide no built-in authentication or encryption.

How to share a serial port over LAN on Linux

If you want to redirect a Linux serial port without buying anything, recent Linux distributions include tools that can do it.

The netcat method

The simplest form pipes a serial device to a network host:

netcat www.example.com port < /dev/ttyS0

Note: this approach requires a new instance of netcat for each connection you want to create. For a persistent connection, create an xinetd service with the following configuration:

service testservice {

port = 5900

socket_type = stream

protocol = tcp

wait = yes

user = root

server = /usr/bin/netcat

server_args = "-l 5900 < /dev/ttyS0"

Change /dev/ttyS0 to your serial port. To configure port parameters such as baud rate and parity, use stty or setserial.

Access and share the serial port with socat

socat is a more capable tool for bridging serial devices over TCP/IP. On the server side, bind the serial device to a TCP port:

socat TCP-LISTEN:PORT,reuseaddr,fork FILE:/dev/ttyUSB0,b115200,raw,echo=0

On the client side, socat creates a pseudo-terminal (PTY) that local serial tools can open as if it were a real port:

socat PTY,link=/dev/ttyV0,waitslave,raw,echo=0 TCP:SERVER_IP:PORT

The fork option handles multiple connections, and flow control can be configured through additional options. socat is flexible and free, but note that it provides no authentication or encryption of its own, see the security section above before using it across an untrusted network.

For occasional or scripted access on Linux, netcat and socat are often all you need. Where they fall short is persistent multi-client setups, virtual COM ports on Windows clients, and anything that needs to survive reboots without custom service scripts.

Serial to Ethernet Connector

Access COM port over LAN

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