Network and firewall requirements

When to use this: BitMed Link is installed and paired, but the counters cannot see each other — or your IT person wants to know exactly what to allow.

BitMed Link uses the local network to communicate between counter PCs. For counters to sync correctly, every counter must be on the same local network and must be able to communicate directly with the other counters.

What the network must allow

Your store network should meet these requirements:

All counter PCs are connected to the same local network.
Each counter can communicate directly with the other counters.
A standard router or network switch is sufficient.
Both Ethernet and Wi-Fi are supported. A wired connection is recommended when possible because it is usually more stable.
You can mix wired and Wi-Fi connections as long as all counters are on the same network.

Important: Do not connect different counters to separate networks. For example, a counter connected to a mobile hotspot will not be able to sync locally with counters connected to the store's Wi-Fi.

Ports used by BitMed Link

BitMed Link uses the following local ports:

Port	Protocol	Direction	Purpose
47832	TCP	Inbound; restrict to the trusted store network	Transfers sync data between counters
47833	UDP	Inbound; restrict to the trusted store network	Allows counters to discover each other
47831	TCP	Local PC only	Provides the BitMed Link local service and health endpoint

The installer normally creates the required Windows Firewall rules automatically. Those rules may allow connections from any address on any network profile, so installation alone does not restrict access to the store network. Ask your IT team to review the rules, particularly on a PC that also connects to public Wi-Fi or a mobile hotspot.

Port 47831 (local service)

Port 47831 is used by the BitMed Link service on the same PC. Its local health endpoint is:

http://127.0.0.1:47831/v1/health

This endpoint is only reachable from the same PC.

Ports 47832 and 47833 (counter-to-counter)

These ports are used for communication between counter PCs:

TCP 47832 — counter-to-counter sync data.
UDP 47833 — counter discovery.

They only need to be accessible on the local store network.

Security: You do not need to open these ports on the internet router or configure port forwarding. BitMed Link does not require incoming connections from outside the store network.

Network settings that can prevent sync

If BitMed Link is installed and paired correctly but counters cannot see each other, check the following settings.

1. Client or AP isolation is enabled

Symptom: Counters are on the same Wi-Fi but never see each other.
Cause: Some routers isolate devices from one another. The setting may be called Client Isolation, AP Isolation, Wireless Isolation or Guest Network Isolation.
Fix: Disable isolation for the store network, or connect the counter PCs to a network where local device-to-device communication is allowed. Do not use the router's Guest Wi-Fi for counter PCs if it prevents local communication.

2. Counters are on different networks

Symptom: Every counter has internet access, but they cannot communicate with each other.
Cause: The counters are on different networks — for example, Counter A is on the store Wi-Fi and Counter B is on another router.
Fix: Connect all counters to the same local network.

3. A counter is using a mobile hotspot

Symptom: One counter syncs with nobody while the rest sync normally.
Cause: A counter connected to a mobile hotspot is normally on a different network from the store's other counters.
Fix: Connect the counter to the same store network as the other counters.

4. Antivirus or third-party firewall is blocking BitMed Link

Symptom: Windows Firewall allows BitMed Link, but counters still cannot connect.
Cause: Another security application is blocking BitMed Link on the local network.
Fix: Check your antivirus or firewall settings and allow BitMed Link to communicate on the local network.
- If your security software allows applications by path, the program is normally located at the path below. If your installation uses a different location, use the actual BitMed Link installation path.
- The required local ports are TCP 47832 and UDP 47833.

C:\Program Files\BitMed_Link\bitmedlink.exe

5. Windows network is set to Public

Symptom: Counters could connect before, or connect on one PC but not another.
Cause: Windows applies stricter firewall rules to networks marked Public.
Fix: For a trusted store network, open Settings → Network & internet → Wi-Fi/Ethernet → Network profile and set the store network to Private if appropriate for your environment.

Only mark a network as Private when you trust the network and understand who can connect to it.

Add the firewall rules manually

Normally, the BitMed Link installer creates the firewall rules for you. Use the following steps only if:

The firewall rules were removed.
Your IT team manages Windows Firewall manually.
BitMed Link diagnostics reports that the required ports are blocked.

These examples restrict access to the local subnet on Private and Domain networks, and to the installed BitMed Link program. If you installed it elsewhere, replace the program path in the commands. Ask your IT team to adapt the subnet restriction if your store uses several routed subnets.

Open PowerShell as Administrator, then run the steps below in order.

Step 1: Disable existing rules

Disable any existing rules with the installer's display names, so a broader rule does not override the restriction:

Get-NetFirewallRule -DisplayName "BitMed Link - Peer Sync (TCP 47832)", "BitMed Link - LAN Discovery (UDP 47833)" -ErrorAction SilentlyContinue | Disable-NetFirewallRule

Step 2: Create the sync rule (TCP 47832)

New-NetFirewallRule -DisplayName "BitMed Link - Peer Sync (TCP 47832)" -Direction Inbound -Protocol TCP -LocalPort 47832 -Action Allow -Profile Private,Domain -RemoteAddress LocalSubnet -Program "C:\Program Files\BitMed_Link\bitmedlink.exe"

Step 3: Create the discovery rule (UDP 47833)

New-NetFirewallRule -DisplayName "BitMed Link - LAN Discovery (UDP 47833)" -Direction Inbound -Protocol UDP -LocalPort 47833 -Action Allow -Profile Private,Domain -RemoteAddress LocalSubnet -Program "C:\Program Files\BitMed_Link\bitmedlink.exe"

Step 4: Restart and test

Restart BitMed Link and test the connection again.

Re-running the installer can restore its default firewall rules. If your IT team has restricted them, have the team check and reapply that policy after a repair or update.

Does each counter need a fixed IP address?

No. BitMed Link discovers counters automatically on the local network, so you do not normally need to assign a static IP address to each counter.

A counter can receive a different IP address from the router after a restart and still work normally, as long as it remains on the same local network and local communication is allowed.

Quick checklist

If counters are not syncing, check these items in order:

Same network — all counters are connected to the same store network.
Local communication — client/AP isolation is disabled.
Not a guest network — counters are not using an isolated Guest Wi-Fi.
BitMed Link running — the BitMed Link service is running on every counter.
Firewall — TCP 47832 and UDP 47833 are allowed on the local network.
Security software — antivirus or third-party firewall is not blocking BitMed Link.
Network profile — the trusted store network is configured as Private where appropriate.

After making any network or firewall changes, restart BitMed Link and test syncing between two counters again — see a counter is not syncing if it still does not work.