[GH-ISSUE #757] [Bug]: Virtual Printer proxy mode: Bambu Studio tries to connect to phyiscal IP when starting printing

bambuddy-support-20260319-070439.zip

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Originally created by @Utility9298 on GitHub (Mar 19, 2026).
Original GitHub issue: https://github.com/maziggy/bambuddy/issues/757

Originally assigned to: @maziggy on GitHub.

Bug Description

When trying to print from Bambu Studio to a virtual printer in proxy mode, Bambu Studio shows a pop with pre-filled phyiscal IP adress of the printer and asks for the access code.

The virtual printer are found automatically in Bambu Studio, I made sure that Bambu Studio is not able to see the physical printers.

Expected Behavior

Bambu Studio sends the print to the virtual printer and BamBuddy sends it to the physical printer.

Steps to Reproduce

Running Debian as a Virtual Machine on Proxmox
The VM has 2 Network adapter:

# 192.168.73.1 / 24 -> Office VLAN
auto ens18
iface ens18 inet static
        address 192.168.73.10
        netmask 255.255.255.0
        gateway 192.168.73.1
        dns-nameservers 8.8.8.8

        up ip addr add 192.168.73.11/24 dev ens18
        up ip addr add 192.168.73.12/24 dev ens18
        up ip addr add 192.168.73.13/24 dev ens18

        down ip addr del 192.168.73.11/24 dev ens18
        down ip addr del 192.168.73.12/24 dev ens18
        down ip addr del 192.168.73.13/24 dev ens18

# 10.73.51.230 / 24 -> Printer VLAN
auto ens19
iface ens19 inet static
        address 10.73.51.230
        netmask 255.255.255.0

BamBuddy is running as docker with network mode host

services:
  bambuddy:
#    image: ghcr.io/maziggy/bambuddy:latest
    image: ghcr.io/maziggy/bambuddy:0.2.3b1-daily.20260318
    build: .
    container_name: bambuddy
    network_mode: host  # Recommended for automatic printer discovery
    cap_add:
      - NET_BIND_SERVICE #Required for virtual printer proxy (port 990)
    volumes:
      - bambuddy_data:/app/data
      - bambuddy_logs:/app/logs
    environment:
      - TZ=Europe/Vienna  # Your timezone
    restart: unless-stopped

volumes:
  bambuddy_data:
  bambuddy_logs:

Bambu Studio can find and connect to the virtual printers, BamBuddy is able to find the physical printers.
Connect BambuStudio to the virtual printers -> Works
Print to the virtual printer -> Dialog opens with physical IP address pre-filled and asks for access code

I did also try to add several network adapters (for each printer a dedicated network adapter) but it did not change the behaviour. Also tried the network override on virtual printer settings.

Printer Model

A1

Bambuddy Version

0.2.3b1

Printer Firmware Version

01.07.02.00

Installation Method

Docker

Operating System

Linux (Ubuntu/Debian)

Relevant Logs / Support Package

Screenshots

BambuStudio asking for access code on the physical IP adress when printing:

Additional Context

No response

Checklist

I have searched existing issues to ensure this bug hasn't already been reported
I am using the latest version of Bambuddy
My printer is set to LAN Only mode
My printer has Developer Mode enabled

Originally created by @Utility9298 on GitHub (Mar 19, 2026). Original GitHub issue: https://github.com/maziggy/bambuddy/issues/757 Originally assigned to: @maziggy on GitHub. ### Bug Description When trying to print from Bambu Studio to a virtual printer in proxy mode, Bambu Studio shows a pop with pre-filled phyiscal IP adress of the printer and asks for the access code. The virtual printer are found automatically in Bambu Studio, I made sure that Bambu Studio is not able to see the physical printers. ### Expected Behavior Bambu Studio sends the print to the virtual printer and BamBuddy sends it to the physical printer. ### Steps to Reproduce 1. Running Debian as a Virtual Machine on Proxmox 2. The VM has 2 Network adapter: ``` # 192.168.73.1 / 24 -> Office VLAN auto ens18 iface ens18 inet static address 192.168.73.10 netmask 255.255.255.0 gateway 192.168.73.1 dns-nameservers 8.8.8.8 up ip addr add 192.168.73.11/24 dev ens18 up ip addr add 192.168.73.12/24 dev ens18 up ip addr add 192.168.73.13/24 dev ens18 down ip addr del 192.168.73.11/24 dev ens18 down ip addr del 192.168.73.12/24 dev ens18 down ip addr del 192.168.73.13/24 dev ens18 # 10.73.51.230 / 24 -> Printer VLAN auto ens19 iface ens19 inet static address 10.73.51.230 netmask 255.255.255.0 ``` 3. BamBuddy is running as docker with network mode host ``` services: bambuddy: # image: ghcr.io/maziggy/bambuddy:latest image: ghcr.io/maziggy/bambuddy:0.2.3b1-daily.20260318 build: . container_name: bambuddy network_mode: host # Recommended for automatic printer discovery cap_add: - NET_BIND_SERVICE #Required for virtual printer proxy (port 990) volumes: - bambuddy_data:/app/data - bambuddy_logs:/app/logs environment: - TZ=Europe/Vienna # Your timezone restart: unless-stopped volumes: bambuddy_data: bambuddy_logs: ``` 4. Bambu Studio can find and connect to the virtual printers, BamBuddy is able to find the physical printers. 5. Connect BambuStudio to the virtual printers -> Works 6. Print to the virtual printer -> Dialog opens with physical IP address pre-filled and asks for access code I did also try to add several network adapters (for each printer a dedicated network adapter) but it did not change the behaviour. Also tried the network override on virtual printer settings. ### Printer Model A1 ### Bambuddy Version 0.2.3b1 ### Printer Firmware Version 01.07.02.00 ### Installation Method Docker ### Operating System Linux (Ubuntu/Debian) ### Relevant Logs / Support Package [bambuddy-support-20260319-070439.zip](https://github.com/user-attachments/files/26107239/bambuddy-support-20260319-070439.zip) ### Screenshots BambuStudio asking for access code on the physical IP adress when printing: <img width="712" height="723" alt="Image" src="https://github.com/user-attachments/assets/227f0886-c2cf-40ee-9a92-b63b91bafdc8" /> ### Additional Context _No response_ ### Checklist - [x] I have searched existing issues to ensure this bug hasn't already been reported - [x] I am using the latest version of Bambuddy - [x] My printer is set to LAN Only mode - [x] My printer has Developer Mode enabled

BreizhHardware

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BreizhHardware commented

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@maziggy commented on GitHub (Mar 19, 2026):

I completely re-wrote the proxy to make it more reliable for different network setups. Please use latest daily build and let me know if it works for you.

docker pull ghcr.io/maziggy/bambuddy:daily

Please note: requirements for the VP proxy have changed. Please check https://raw.githubusercontent.com/maziggy/bambuddy/refs/heads/dev/docs/migration-vp-ftp-port.md and updates Wiki docs.

@maziggy commented on GitHub (Mar 19, 2026): I completely re-wrote the proxy to make it more reliable for different network setups. Please use latest daily build and let me know if it works for you. docker pull ghcr.io/maziggy/bambuddy:daily Please note: requirements for the VP proxy have changed. Please check https://raw.githubusercontent.com/maziggy/bambuddy/refs/heads/dev/docs/migration-vp-ftp-port.md and updates Wiki docs.

BreizhHardware commented

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@Utility9298 commented on GitHub (Mar 19, 2026):

I double checked: my server does not have an iptable routing from 990 to 9990.

my compose - file:

services:
  bambuddy:
#    image: ghcr.io/maziggy/bambuddy:latest
    image: ghcr.io/maziggy/bambuddy:daily
    build: .
    container_name: bambuddy
    network_mode: host  # Recommended for automatic printer discovery
    cap_add:
      - NET_BIND_SERVICE #Required for virtual printer proxy (port 990)
    volumes:
      - bambuddy_data:/app/data
      - bambuddy_logs:/app/logs
    environment:
      - TZ=Europe/Vienna  # Your timezone
    restart: unless-stopped

volumes:
  bambuddy_data:
  bambuddy_logs:

Still receiving a pop-up, but at least it shows now the IP of the virtual printer:

@Utility9298 commented on GitHub (Mar 19, 2026): I double checked: my server does not have an iptable routing from 990 to 9990. my compose - file: ``` services: bambuddy: # image: ghcr.io/maziggy/bambuddy:latest image: ghcr.io/maziggy/bambuddy:daily build: . container_name: bambuddy network_mode: host # Recommended for automatic printer discovery cap_add: - NET_BIND_SERVICE #Required for virtual printer proxy (port 990) volumes: - bambuddy_data:/app/data - bambuddy_logs:/app/logs environment: - TZ=Europe/Vienna # Your timezone restart: unless-stopped volumes: bambuddy_data: bambuddy_logs: ``` Still receiving a pop-up, but at least it shows now the IP of the virtual printer: <img width="436" height="577" alt="Image" src="https://github.com/user-attachments/assets/95338abc-1a58-485e-bb1c-f489fcbd341d" />

BreizhHardware commented

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@maziggy commented on GitHub (Mar 19, 2026):

Don't think that this is the access code from you printer's display ;)

@maziggy commented on GitHub (Mar 19, 2026): Don't think that this is the access code from you printer's display ;)

BreizhHardware commented

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@maziggy commented on GitHub (Mar 19, 2026):

And you need to connect to the IP address of the VP assigned interface.

@maziggy commented on GitHub (Mar 19, 2026): And you need to connect to the IP address of the VP assigned interface.

BreizhHardware commented

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@Utility9298 commented on GitHub (Mar 19, 2026):

It is the access code from the printer:

IP of the virtual printer: 192.168.73.13
IP of the phyiscal printer: 10.73.51.85

@Utility9298 commented on GitHub (Mar 19, 2026): It is the access code from the printer: IP of the virtual printer: 192.168.73.13 IP of the phyiscal printer: 10.73.51.85 <img width="527" height="422" alt="Image" src="https://github.com/user-attachments/assets/f4186fdc-8980-4e1b-8bea-4402a667a6dd" /> <img width="490" height="699" alt="Image" src="https://github.com/user-attachments/assets/f0405183-0714-4190-bbf5-5fd4b5b27fe1" />

BreizhHardware commented

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@maziggy commented on GitHub (Mar 19, 2026):

Sorry, but need to double check. Are you sure running the daily image i just pushed some minutes ago?

If so, please upload new debug logs.

@maziggy commented on GitHub (Mar 19, 2026): Sorry, but need to double check. Are you sure running the daily image i just pushed some minutes ago? If so, please upload new debug logs.

BreizhHardware commented

bambuddy-support-20260319-162722.zip

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@Utility9298 commented on GitHub (Mar 19, 2026):

v0.2.3b1: docker compose pull with bambuddy:daily is telling me state "pulled"

Here is the debug log:

@Utility9298 commented on GitHub (Mar 19, 2026): v0.2.3b1: docker compose pull with bambuddy:daily is telling me state "pulled" Here is the debug log: [bambuddy-support-20260319-162722.zip](https://github.com/user-attachments/files/26120141/bambuddy-support-20260319-162722.zip)

BreizhHardware commented

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@maziggy commented on GitHub (Mar 19, 2026):

Cany ou please try with your X1C? I did comprehensive testing today with a H2D and a X1C. Just to rule-out that there is something different with the the A1. Thanks.

@maziggy commented on GitHub (Mar 19, 2026): Cany ou please try with your X1C? I did comprehensive testing today with a H2D and a X1C. Just to rule-out that there is something different with the the A1. Thanks.

BreizhHardware commented

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@fadudba commented on GitHub (Mar 19, 2026):

I’m seeing very similar behavior on my side.

My setup:
• Synology NAS
• Bambuddy in Docker with network_mode: host
• NET_BIND_SERVICE enabled
• real printer is an A1 Mini
• printer is in LAN Only Mode with Developer Mode enabled
• Bambuddy virtual printer is configured in Proxy mode

What I did:
• created a dedicated secondary IP on the NAS for the virtual printer
• set Bambuddy to bind the virtual printer to that dedicated IP
• set the Network Interface Override to that same IP/interface
• added Bambuddy’s CA certificate to Bambu Studio’s printer.cer
• added the virtual printer in Bambu Studio using the real printer’s access code

What happens:
• Bambu Studio don't let me add my virtual printer manually
• Bambuddy logs show the proxy services starting correctly and Bambu Studio reaching ports like 3000/3002/8883
• but the connection is still unstable, and the behavior feels like Studio is trying to fall back to the physical printer path instead of staying fully on the proxy path

@fadudba commented on GitHub (Mar 19, 2026): I’m seeing very similar behavior on my side. My setup: • Synology NAS • Bambuddy in Docker with network_mode: host • NET_BIND_SERVICE enabled • real printer is an A1 Mini • printer is in LAN Only Mode with Developer Mode enabled • Bambuddy virtual printer is configured in Proxy mode What I did: • created a dedicated secondary IP on the NAS for the virtual printer • set Bambuddy to bind the virtual printer to that dedicated IP • set the Network Interface Override to that same IP/interface • added Bambuddy’s CA certificate to Bambu Studio’s printer.cer • added the virtual printer in Bambu Studio using the real printer’s access code What happens: • Bambu Studio don't let me add my virtual printer manually • Bambuddy logs show the proxy services starting correctly and Bambu Studio reaching ports like 3000/3002/8883 • but the connection is still unstable, and the behavior feels like Studio is trying to fall back to the physical printer path instead of staying fully on the proxy path

BreizhHardware commented

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@maziggy commented on GitHub (Mar 19, 2026):

You need to be careful! If you enable VP proxy mode and the slicer can reach your printer directly, then the slicer is receiving duplicate SSDP advertisements - one from Bambuddy and one directly from the printer.

And if you can reach the printer directly, you don't need proxy mode.

@maziggy commented on GitHub (Mar 19, 2026): You need to be careful! If you enable VP proxy mode and the slicer can reach your printer directly, then the slicer is receiving duplicate SSDP advertisements - one from Bambuddy and one directly from the printer. And if you can reach the printer directly, you don't need proxy mode.

BreizhHardware commented

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@Utility9298 commented on GitHub (Mar 20, 2026):

Cany ou please try with your X1C? I did comprehensive testing today with a H2D and a X1C. Just to rule-out that there is something different with the the A1. Thanks.

You are right. The P2S, H2C and the X1 Carbon are working now.

The A1 still brings up the connection-screen.

@Utility9298 commented on GitHub (Mar 20, 2026): > Cany ou please try with your X1C? I did comprehensive testing today with a H2D and a X1C. Just to rule-out that there is something different with the the A1. Thanks. You are right. The P2S, H2C and the X1 Carbon are working now. The A1 still brings up the connection-screen.

BreizhHardware commented

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@maziggy commented on GitHub (Mar 20, 2026):

Thanks for the detailed testing and logs! We've confirmed the proxy infrastructure itself works correctly for the A1 — MQTT, FTP, and bind connections all succeed. The issue is that BambuStudio still rejects the printer despite successful connections, which means BS is doing something A1-specific that we're not handling yet.

We've added diagnostic probing in the latest dev branch to detect if BambuStudio tries to connect on ports we don't proxy (21, 80, 443).

Can you test with the dev branch?

git clone -b dev https://github.com/maziggy/bambuddy.git
cd bambuddy
docker compose up --build -d

Then try adding the A1 in BambuStudio and upload new debug logs. We're looking for any PROBE: warnings in the log — they'll tell us if BS connects on a port we don't handle.

Also, can you test one more thing? Temporarily change your A1 virtual printer's model to X1 Carbon in the VP settings, then try adding it in BambuStudio again. If it works as X1C but not as A1, we know the issue is model-specific in BambuStudio's connection flow. You can change it back afterwards.

If you can also run a tcpdump, that would give us the complete picture:

docker exec bambuddy tcpdump -i any host <SLICER_IP> -nn -w /tmp/a1-proxy.pcap

docker cp bambuddy:/tmp/a1-proxy.pcap .

This will show us every port BambuStudio tries to connect to.

@maziggy commented on GitHub (Mar 20, 2026): Thanks for the detailed testing and logs! We've confirmed the proxy infrastructure itself works correctly for the A1 — MQTT, FTP, and bind connections all succeed. The issue is that BambuStudio still rejects the printer despite successful connections, which means BS is doing something A1-specific that we're not handling yet. We've added diagnostic probing in the latest dev branch to detect if BambuStudio tries to connect on ports we don't proxy (21, 80, 443). Can you test with the dev branch? git clone -b dev https://github.com/maziggy/bambuddy.git cd bambuddy docker compose up --build -d Then try adding the A1 in BambuStudio and upload new debug logs. We're looking for any PROBE: warnings in the log — they'll tell us if BS connects on a port we don't handle. Also, can you test one more thing? Temporarily change your A1 virtual printer's model to X1 Carbon in the VP settings, then try adding it in BambuStudio again. If it works as X1C but not as A1, we know the issue is model-specific in BambuStudio's connection flow. You can change it back afterwards. If you can also run a tcpdump, that would give us the complete picture: docker exec bambuddy tcpdump -i any host <SLICER_IP> -nn -w /tmp/a1-proxy.pcap docker cp bambuddy:/tmp/a1-proxy.pcap . This will show us every port BambuStudio tries to connect to.

BreizhHardware commented

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@Utility9298 commented on GitHub (Mar 20, 2026):

I will test this and share my results next monday, I am off the office for this weekend and do not have access to Bambuddy / the printers.

@Utility9298 commented on GitHub (Mar 20, 2026): I will test this and share my results next monday, I am off the office for this weekend and do not have access to Bambuddy / the printers.

BreizhHardware commented

bambuddy-support-20260323-072422.zip

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@Utility9298 commented on GitHub (Mar 23, 2026):

Testing with v.0.2.2.1:

Temporarily change your A1 virtual printer's model to X1 Carbon in the VP settings

I do use proxy mode - but for testing I switched to queue and used the virtual A1 -> Works when using "send" to send files to the queue directly from BambuStudio.

Here is the tcpdump (I did run it from the host because tcpdump seems not to be available in the bambuddy container):

a1-proxy.zip
My testing IP is the 192.168.73.74

And the debug log file from bambuddy:

@Utility9298 commented on GitHub (Mar 23, 2026): Testing with v.0.2.2.1: > Temporarily change your A1 virtual printer's model to X1 Carbon in the VP settings I do use proxy mode - but for testing I switched to queue and used the virtual A1 -> Works when using "send" to send files to the queue directly from BambuStudio. Here is the tcpdump (I did run it from the host because tcpdump seems not to be available in the bambuddy container): [a1-proxy.zip](https://github.com/user-attachments/files/26174612/a1-proxy.zip) My testing IP is the 192.168.73.74 And the debug log file from bambuddy: [bambuddy-support-20260323-072422.zip](https://github.com/user-attachments/files/26174630/bambuddy-support-20260323-072422.zip)

BreizhHardware commented

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@maziggy commented on GitHub (Mar 23, 2026):

Did you check release notes for 0.2.2.1? There are changes required for the changed proxy function.

@maziggy commented on GitHub (Mar 23, 2026): Did you check release notes for 0.2.2.1? There are changes required for the changed proxy function.

BreizhHardware commented

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@Utility9298 commented on GitHub (Mar 23, 2026):

Yes, I did this already before testing with 0.2.3b1.
The other printers work fine - only the a1 is making trouble.

Runnind docker with network_mode: host and the cap_add: - NET_BIND_SERVICE #Required for virtual printer proxy (port 990).
Also there are no existing iptables any more:

sudo iptables -t nat -L PREROUTING -n | grep 9990 -> Empty output

@Utility9298 commented on GitHub (Mar 23, 2026): Yes, I did this already before testing with 0.2.3b1. The other printers work fine - only the a1 is making trouble. Runnind docker with `network_mode: host` and the `cap_add: - NET_BIND_SERVICE #Required for virtual printer proxy (port 990)`. Also there are no existing iptables any more: `sudo iptables -t nat -L PREROUTING -n | grep 9990` -> Empty output

BreizhHardware commented

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@maziggy commented on GitHub (Mar 23, 2026):

Your tcpdump is very helpful!

It looks like the A1 is also using port 2024 which is not used by any other model. Need to find out what's happening on this port.

@maziggy commented on GitHub (Mar 23, 2026): Your tcpdump is very helpful! It looks like the A1 is also using port 2024 which is not used by any other model. Need to find out what's happening on this port.

BreizhHardware commented

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@Utility9298 commented on GitHub (Mar 23, 2026):

I did upgrade the firmware on the a1 before adding it to bambuddy to version 01.07.02.00.

If I can do anything to help in debugging let me know - I can try an older firmware if a downgrade is even possible

@Utility9298 commented on GitHub (Mar 23, 2026): I did upgrade the firmware on the a1 before adding it to bambuddy to version 01.07.02.00. If I can do anything to help in debugging let me know - I can try an older firmware if a downgrade is even possible

BreizhHardware commented

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@maziggy commented on GitHub (Mar 23, 2026):

Added proxy for port 2024-2026.

Please use dev branch and rebuild the image

git checkout dev && git pull && docker compose down && docker compose up -d --build

and try again. Please enable debug logging before testing.

Also can you please scan for open ports on your A1?
nmap -sT -p- <A1_PHYSICAL_IP>

@maziggy commented on GitHub (Mar 23, 2026): Added proxy for port 2024-2026. Please use dev branch and rebuild the image git checkout dev && git pull && docker compose down && docker compose up -d --build and try again. Please enable debug logging before testing. Also can you please scan for open ports on your A1? nmap -sT -p- <A1_PHYSICAL_IP>

BreizhHardware commented

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@Utility9298 commented on GitHub (Mar 23, 2026):

No open ports on 2024 found:

nmap -sT -p- 10.73.51.85
Starting Nmap 7.95 ( https://nmap.org ) at 2026-03-23 10:54 CET
Nmap scan report for 10.73.51.85
Host is up (0.0085s latency).
Not shown: 65530 closed tcp ports (conn-refused)
PORT     STATE SERVICE
990/tcp  open  ftps
3000/tcp open  ppp
3002/tcp open  exlm-agent
6000/tcp open  X11
8883/tcp open  secure-mqtt

Nmap done: 1 IP address (1 host up) scanned in 24.80 seconds

Seems like I can't find any virtual printer with the dev branch. No printers are shown in BambuStudio and can't connect them manually.

Another interesting thing showing a difference beetween A1 and the other printers:

@Utility9298 commented on GitHub (Mar 23, 2026): No open ports on 2024 found: ``` nmap -sT -p- 10.73.51.85 Starting Nmap 7.95 ( https://nmap.org ) at 2026-03-23 10:54 CET Nmap scan report for 10.73.51.85 Host is up (0.0085s latency). Not shown: 65530 closed tcp ports (conn-refused) PORT STATE SERVICE 990/tcp open ftps 3000/tcp open ppp 3002/tcp open exlm-agent 6000/tcp open X11 8883/tcp open secure-mqtt Nmap done: 1 IP address (1 host up) scanned in 24.80 seconds ``` Seems like I can't find any virtual printer with the dev branch. No printers are shown in BambuStudio and can't connect them manually. Another interesting thing showing a difference beetween A1 and the other printers: <img width="1214" height="1033" alt="Image" src="https://github.com/user-attachments/assets/9f3609bf-fe4d-4ed2-b433-ae3400262997" />

BreizhHardware commented

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@maziggy commented on GitHub (Mar 23, 2026):

Port 2024 finding: Very interesting that the A1 doesn't have port 2024 open. This means BambuStudio is trying to connect to port 2024 on the printer/VP IP, but the A1 itself doesn't serve anything there. Two possibilities:

The A1 opens port 2024 only temporarily during certain operations (nmap wouldn't catch it)
BambuStudio just does a connectivity check on that port for A1 models

Either way, the proxy accepting and attempting to forward will currently fail upstream. We may need to handle this differently — possibly just accept and close the connection gracefully instead of proxying it.

VP discovery not working on dev: The only VP code change on dev (vs 0.2.2.1) is the port 2024-2026 proxy addition — SSDP discovery code is identical. This is likely a build/config issue rather than a code regression. Can you please

enable debug logging
restart bambuddy
try to connect to A1 VP proxy
upload support-package

If you can share the logs from the dev branch attempt, that would help narrow it down.

Thanks!

@maziggy commented on GitHub (Mar 23, 2026): Port 2024 finding: Very interesting that the A1 doesn't have port 2024 open. This means BambuStudio is trying to connect to port 2024 on the printer/VP IP, but the A1 itself doesn't serve anything there. Two possibilities: 1. The A1 opens port 2024 only temporarily during certain operations (nmap wouldn't catch it) 2. BambuStudio just does a connectivity check on that port for A1 models Either way, the proxy accepting and attempting to forward will currently fail upstream. We may need to handle this differently — possibly just accept and close the connection gracefully instead of proxying it. VP discovery not working on dev: The only VP code change on dev (vs 0.2.2.1) is the port 2024-2026 proxy addition — SSDP discovery code is identical. This is likely a build/config issue rather than a code regression. Can you please 1. enable debug logging 2. restart bambuddy 3. try to connect to A1 VP proxy 4. upload support-package If you can share the logs from the dev branch attempt, that would help narrow it down. Thanks!

BreizhHardware commented

bambuddy-support-20260323-115954.zip

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@Utility9298 commented on GitHub (Mar 23, 2026):

I hope I did nothing wrong when building the image (I am a git noob).

Here is the debug log with the developer version, as you described I:

Enabled debug logging
restarted bambuddy
And tried to connect to the virtual proxy A1

@Utility9298 commented on GitHub (Mar 23, 2026): I hope I did nothing wrong when building the image (I am a git noob). Here is the debug log with the developer version, as you described I: 1. Enabled debug logging 2. restarted bambuddy 3. And tried to connect to the virtual proxy A1 [bambuddy-support-20260323-115954.zip](https://github.com/user-attachments/files/26180263/bambuddy-support-20260323-115954.zip)

BreizhHardware commented

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@maziggy commented on GitHub (Mar 23, 2026):

2026-03-23 11:59:04,593 ERROR [backend.app.services.virtual_printer.manager] Cannot create directory /app/data/virtual_printer/uploads: Permission denied. For Docker: ensure the data volume is writable by the container user. For bare metal: run 'sudo chown -R $(whoami) /app/data/virtual_printer'
2026-03-23 11:59:04,593 ERROR [backend.app.services.virtual_printer.manager] Cannot create directory /app/data/virtual_printer/certs: Permission denied. For Docker: ensure the data volume is writable by the container user. For bare metal: run 'sudo chown -R $(whoami) /app/data/virtual_printer'
2026-03-23 11:59:04,607 WARNING [root] Failed to sync virtual printers: [Errno 13] Permission denied: '/app/data/virtual_printer/uploads'

@maziggy commented on GitHub (Mar 23, 2026): 2026-03-23 11:59:04,593 ERROR [backend.app.services.virtual_printer.manager] Cannot create directory /app/data/virtual_printer/uploads: Permission denied. For Docker: ensure the data volume is writable by the container user. For bare metal: run 'sudo chown -R $(whoami) /app/data/virtual_printer' 2026-03-23 11:59:04,593 ERROR [backend.app.services.virtual_printer.manager] Cannot create directory /app/data/virtual_printer/certs: Permission denied. For Docker: ensure the data volume is writable by the container user. For bare metal: run 'sudo chown -R $(whoami) /app/data/virtual_printer' 2026-03-23 11:59:04,607 WARNING [root] Failed to sync virtual printers: [Errno 13] Permission denied: '/app/data/virtual_printer/uploads'

BreizhHardware commented

bambuddy-support-20260323-161330.zip

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Owner

@Utility9298 commented on GitHub (Mar 23, 2026):

My mistake - Didn't see the the user mapping in the dev compose file.

But the print worked now. I was able to select the virtual A1 in proxy mode and start the print directly from BambuStudio.
So it is really something with port 2024 which is most likely temporarily opened on the printer?

@Utility9298 commented on GitHub (Mar 23, 2026): My mistake - Didn't see the the user mapping in the dev compose file. But the print worked now. I was able to select the virtual A1 in proxy mode and start the print directly from BambuStudio. So it is really something with port 2024 which is most likely temporarily opened on the printer? [bambuddy-support-20260323-161330.zip](https://github.com/user-attachments/files/26186216/bambuddy-support-20260323-161330.zip)

BreizhHardware commented

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@maziggy commented on GitHub (Mar 23, 2026):

Looks good according to the logs.

So is your issue resolved now?

@maziggy commented on GitHub (Mar 23, 2026): Looks good according to the logs. So is your issue resolved now?

BreizhHardware commented

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Owner

@Utility9298 commented on GitHub (Mar 23, 2026):

Yes, the A1 is printing now.
Thank you very much!

@Utility9298 commented on GitHub (Mar 23, 2026): Yes, the A1 is printing now. Thank you very much!

BreizhHardware commented

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@maziggy commented on GitHub (Mar 23, 2026):

If you find Bambuddy useful, please consider giving it a ⭐ on GitHub — it helps others discover the project!

@maziggy commented on GitHub (Mar 23, 2026): ----- If you find Bambuddy useful, please consider giving it a ⭐ on [GitHub](https://github.com/maziggy/bambuddy) — it helps others discover the project!

BreizhHardware commented

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@Christophe999s commented on GitHub (Mar 25, 2026):

Port 2024 finding: Very interesting that the A1 doesn't have port 2024 open. This means BambuStudio is trying to connect to port 2024 on the printer/VP IP, but the A1 itself doesn't serve anything there. Two possibilities:

The A1 opens port 2024 only temporarily during certain operations (nmap wouldn't catch it)

BambuStudio just does a connectivity check on that port for A1 models

Either way, the proxy accepting and attempting to forward will currently fail upstream. We may need to handle this differently — possibly just accept and close the connection gracefully instead of proxying it.

VP discovery not working on dev: The only VP code change on dev (vs 0.2.2.1) is the port 2024-2026 proxy addition — SSDP discovery code is identical. This is likely a build/config issue rather than a code regression. Can you please

enable debug logging

restart bambuddy

try to connect to A1 VP proxy

upload support-package

If you can share the logs from the dev branch attempt, that would help narrow it down.

Thanks!

I was having the same issue when using proxy mode to my P1S. Had to use wireshark to figure out why VP wasn't working when my firewall was enables and I saw that connection attempts were made to port 2024. Added a rule to allow tcp 2024 traffic and VP is working now.
I'm using nftables and these are the ports I have open on the VP network interface: tcp dport { 2024-2026, 3000, 3002, 8883, 990, 6000, 322, 50000-50100 } accept
Could you update the documentation on https://wiki.bambuddy.cool/features/virtual-printer/ for those that come after?

@Christophe999s commented on GitHub (Mar 25, 2026): > Port 2024 finding: Very interesting that the A1 doesn't have port 2024 open. This means BambuStudio is trying to connect to port 2024 on the printer/VP IP, but the A1 itself doesn't serve anything there. Two possibilities: > > 1. The A1 opens port 2024 only temporarily during certain operations (nmap wouldn't catch it) > 2. BambuStudio just does a connectivity check on that port for A1 models > > Either way, the proxy accepting and attempting to forward will currently fail upstream. We may need to handle this differently — possibly just accept and close the connection gracefully instead of proxying it. > > VP discovery not working on dev: The only VP code change on dev (vs 0.2.2.1) is the port 2024-2026 proxy addition — SSDP discovery code is identical. This is likely a build/config issue rather than a code regression. Can you please > > 1. enable debug logging > 2. restart bambuddy > 3. try to connect to A1 VP proxy > 4. upload support-package > > If you can share the logs from the dev branch attempt, that would help narrow it down. > > Thanks! I was having the same issue when using proxy mode to my P1S. Had to use wireshark to figure out why VP wasn't working when my firewall was enables and I saw that connection attempts were made to port 2024. Added a rule to allow tcp 2024 traffic and VP is working now. I'm using nftables and these are the ports I have open on the VP network interface: tcp dport { 2024-2026, 3000, 3002, 8883, 990, 6000, 322, 50000-50100 } accept Could you update the documentation on https://wiki.bambuddy.cool/features/virtual-printer/ for those that come after?

BreizhHardware commented