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TCP/IP Communication Failure on PNM-C34404RQPZ when Using 172.17.0.0/24 Subnet

Created by: Alex Dias (a.dias@hanwha.com)
Created time: October 2025
Last edited time: October 2025
Product Category: Camera
Resolution Status: Done
ZD KB Article URL: here

1. Issue

On model PNM-C34404RQPZ, all TCP/IP communication fails when the camera is assigned an IP address within 172.17.0.0/24 subnet and accessed from another subnet.
This occurs because the default Docker bridge (docker0) uses the broader 172.17.0.0/16 subnet, leading to routing conflicts.

Other IP ranges (e.g., 172.16.x.x or 192.168.x.x) work normally.

Affected Model & Firmware
- Model: PNM-C34404RQPZ
- Affected Firmware: All firmware prior to v25.01.08 (R1004)

2. Root Cause

An internal Docker daemon uses the default bridge interface docker0 at 172.17.0.1/16.
When the camera is configured with an IP within 172.17.0.0/24 (e.g., 172.17.0.68/24), the Docker bridge’s /16 network overlaps with the camera subnet, causing outbound packets to be misrouted via docker0 instead of the physical interface.

Verification Command

/stw-cgi/debugcgi?msubmenu=shell&command=ifconfig

→ Output shows:

docker0  addr:172.17.0.1  Mask:255.255.0.0

3. Resolution

3-1. Workaround

Avoid assigning camera IPs within the 172.17.0.0/24 subnet when using firmware versions prior to v25.01.08.

3-2. Fix Implementation

Firmware v25.01.08 (R1004, 2025-09-29) introduces logic to detect IP conflicts between the camera’s main interface and Docker’s bridge interface.
If the camera IP overlaps with Docker’s default range (172.17.0.0/16), the system automatically reassigns the Docker bridge IP to a non-conflicting private address range (e.g., 171.17.0.1).

4. Reproduction Steps

4-1. Camera Configuration

  • Assign camera IP: 172.17.200.68/24
  • Default gateway: 172.17.200.1

4-2. Network Topology

  • Camera → Router 1 (172.17.200.1/24)
  • Router 1 → Router 2 → PC 1 (10.204.198.185/24)
  • Router 1 → Router 3 → PC 2 (172.17.98.2/24)

4-3. Test Procedure (Affected Firmware)

  • From PC 1 (10.204.198.185) → Ping camera 172.17.200.68 → ✅ Success
  • From PC 2 (172.17.98.2) → Ping camera 172.17.200.68 → ❌ Fail
  • ifconfig result shows docker0 IP as 172.17.0.1/16

4-4. Test Procedure (Fixed Firmware v25.01.08 or later)

  • Repeat the same setup and tests
  • ✅ Ping succeeds from both PC 1 and PC 2
  • docker0 automatically reassigned (e.g., 171.17.0.1)

5. Verification

  • Reproduced on v25.01.07 (R997) with Docker bridge IP conflict
  • Resolved on v25.01.08 (R1004) – Docker bridge IP dynamically reassigned
  • Confirmed on customer site: 2025-10-10 (ZD#99065)

6. Firmware Release Plan