Firewall rules for video with Home app on different VLAN than homebridge
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**Describe The Problem:**
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I have my IoT devices, including homebridge, segregated to their own VLAN. I have a multicast-relay agent running on my router, and some firewall rules to allow access from my home network to the IoT network and everything works great - except video. Snapshots work. I can get video to work by creating a firewall rule that accepts traffic from the homebridge IP address to my trusted home network - but that pretty much defeats the purpose of isolating the homebridge machine in the IoT network.

Really I just want to know how to create a firewall rule to restrict this traffic without opening up a range of ~16000 ports.

By turning on logging for this firewall rule, I can see that homebridge starts sending UDP traffic in a really wide port range - and netstat from the homebridge machine shows a number of connections open on ports ranging from  ~49000-65500.

**To Reproduce:**
<!-- Steps to reproduce the behavior. -->
Connect an IOS device with the home app to LAN0 (192.168.0.0/24)
Setup homebridge with this plugin on a LAN11 (192.168.11.0/24) with a supported camera.
Enable mDNS relay between the LANs.
Set firewall rules to accept traffic from LAN0 to LAN11.
Set firewall rules to accept established and related traffic in both directions.
Verify IOS device can see snapshot from camera on LAN11 while connected to LAN0.
Attempt to stream from camera.
Connection Fails.
Create firewall rule to accept all UDP traffic from homebridge IP destined to IOS device on LAN0.
Connection succeeds.

example netstat from homebridge machine (192.168.11.46) to iPhone (192.168.0.105):

```
pi@homebridge:/ $ sudo netstat -nputw | grep 192.168.0.105
tcp6       0      0 192.168.11.46:52108     192.168.0.105:49187     ESTABLISHED 22590/homebridge    
tcp6       0      0 192.168.11.46:41081     192.168.0.105:49179     ESTABLISHED 22644/homebridge: h 
tcp6       0      0 192.168.11.46:52101     192.168.0.105:49176     ESTABLISHED 22590/homebridge    
tcp6       0      0 192.168.11.46:54006     192.168.0.105:49180     ESTABLISHED 22643/homebridge: h 
tcp6       0      0 192.168.11.46:52103     192.168.0.105:49182     ESTABLISHED 22590/homebridge    
tcp6       0      0 192.168.11.46:52102     192.168.0.105:49177     ESTABLISHED 22590/homebridge    
tcp6       0      0 192.168.11.46:52105     192.168.0.105:49184     ESTABLISHED 22590/homebridge    
tcp6       0      0 192.168.11.46:52106     192.168.0.105:49185     ESTABLISHED 22590/homebridge    
tcp6       0      0 192.168.11.46:51826     192.168.0.105:49188     ESTABLISHED 22590/homebridge    
tcp6       0      0 192.168.11.46:52107     192.168.0.105:49186     ESTABLISHED 22590/homebridge    
tcp6       0      0 192.168.11.46:54075     192.168.0.105:49181     ESTABLISHED 22656/homebridge: h 
tcp6       0      0 192.168.11.46:52100     192.168.0.105:49175     ESTABLISHED 22590/homebridge    
tcp6       0      0 192.168.11.46:52104     192.168.0.105:49183     ESTABLISHED 22590/homebridge    
tcp6       0      0 192.168.11.46:55295     192.168.0.105:49178     ESTABLISHED 22650/homebridge: h 
```
**Logs:**
<!-- Bug reports that do not contain logs may be closed without warning. -->

Show the Homebridge logs here.
Remove any sensitive information.

```
[10/08/2021, 17:28:55] [Camera ffmpeg] [SecuritySpy Test] Starting video stream: 1280 x 720, 30 fps, 299 kbps (AAC-eld)
[10/08/2021, 17:29:04] [Camera ffmpeg] [SecuritySpy Test] Stopped video stream.
**Homebridge Config:**
```
                {
                    "name": "SecuritySpy Test",
                    "unbridge": true,
                    "videoConfig": {
                        "source": "-rtsp_transport tcp -i rtsp://XXX:XXX@192.168.0.142:8080/++video?cameraNum=0",
                        "stillImageSource": "-i http://XXX:XXX@192.168.0.142:8080/++image?cameraNum=0",
                        "audio": true
                    }
                 }
```json
Show your homebridge config.json here.
Remove any sensitive information, such as your homebridge-gsh / google-smarthome token.
```

**Screenshots:**
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**Environment:**

* **Node.js Version**: <!-- node -v -->
* v14.17.4
* **NPM Version**: <!-- npm -v -->
* 7.20.3
* **Homebridge Version**: <!-- homebridge -V -->
* Initializing HAP-NodeJS v0.9.4...
1.3.4
* **Homebridge Camera FFmpeg Version**:
* v3.1.2
* **Homebridge Config UI X Plugin Version**:
*  v4.41.2
* **Operating System**: <!-- Raspbian / Ubuntu / Debian / Windows / macOS / Docker -->
Raspbian Buster

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