windows 7 (x86)에서 멀티캐스트 전송과 VirtualBox 충돌

VirtualBox 의 Host Only Adapter 가 사용중이면
멀티캐스트가 그쪽으로만 생성되는 경우가 있다.

아래 링크를 참조해서 수정하거나, 해당 어댑터를 사용중지시키면 된다.

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https://www.virtualbox.org/ticket/8698
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Workaround -
1. Open up Network and Sharing Center
2. Click 'Change Adapter Settings'
3. Right click 'VirtualBox Host-Only Network', go to Properties
4. Double click "Internet Protocol Version 4 (TCP/IPv4)' under 'This connection uses the following items'.
5. In the Properties page, click "Advanced..."
6. In the "Advanced TCP/IP Settings", tab "IP Settings", uncheck the box marked "Automatic Metic" and type in 800 or higher.

OK all dialogs and run whatever software could not Recieve multicast.

The problem stems from Microsoft assigning interface Metrics based on the driver's own reported Link speed in Windows 7. Since that's all 1GB, there is a clash on metric. To Confirm, view the metrics for each adapter by opening up Command Line and running:

>netstat -nr

IPv4 Route Table
===========================================================================
Active Routes:
Network Destination        Netmask          Gateway       Interface  Metric
          0.0.0.0          0.0.0.0      10.210.50.1     10.210.50.90     20
      10.210.50.0    255.255.255.0         On-link      10.210.50.90    276
     10.210.50.90  255.255.255.255         On-link      10.210.50.90    276
    10.210.50.255  255.255.255.255         On-link      10.210.50.90    276
        127.0.0.0        255.0.0.0         On-link         127.0.0.1    306
        127.0.0.1  255.255.255.255         On-link         127.0.0.1    306
  127.255.255.255  255.255.255.255         On-link         127.0.0.1    306
     192.168.56.0    255.255.255.0         On-link      192.168.56.1    656
     192.168.56.1  255.255.255.255         On-link      192.168.56.1    656
   192.168.56.255  255.255.255.255         On-link      192.168.56.1    656
        224.0.0.0        240.0.0.0         On-link         127.0.0.1    306
        224.0.0.0        240.0.0.0         On-link      192.168.56.1    656
        224.0.0.0        240.0.0.0         On-link      10.210.50.90    276
  255.255.255.255  255.255.255.255         On-link         127.0.0.1    306
  255.255.255.255  255.255.255.255         On-link      192.168.56.1    656
  255.255.255.255  255.255.255.255         On-link      10.210.50.90    276
===========================================================================

You want your internet/LAN adapter to have the LOWEST Metric for the general 224.xxxx and 225 cases.