我已经挣扎了两天，但还是没有成功。我有两个调制解调器（别问，是一些特殊的东西），使用拨号（PPP）连接。我在 Windows XP 上试过，效果很好。我正在发送单播和广播 UPD 数据包。如果我在 Windows 7 上重复此操作，我只能发送单播数据，广播数据包似乎在某处丢失了。我尝试使用 Microsoft 网络监视器，我可以看到广播数据包正在我的 PPP 连接上接收。但之后，它们就消失了。在内核的某个地方。我真的不明白为什么。我禁用了防火墙、防病毒软件、基本过滤引擎，尝试记录丢弃的数据包Windows 筛选平台，尝试清理 WIN7 机器，但都没有成功。
这是在接口上接收到的示例数据包，但它已更新到达我的应用程序：
No. Time Source Destination Protocol Length Info
1 13:20:56.093380000 192.168.1.50 192.168.1.255 UDP 49 Source port: x11 Destination port: x11
Frame 1: 49 bytes on wire (392 bits), 49 bytes captured (392 bits)
Encapsulation type: Ethernet (1)
Arrival Time: May 7, 2014 13:20:56.093380000 Central Europe Daylight Time
[Time shift for this packet: 0.000000000 seconds]
Epoch Time: 1399461656.093380000 seconds
[Time delta from previous captured frame: 0.000000000 seconds]
[Time delta from previous displayed frame: 0.000000000 seconds]
[Time since reference or first frame: 0.000000000 seconds]
Frame Number: 1
Frame Length: 49 bytes (392 bits)
Capture Length: 49 bytes (392 bits)
[Frame is marked: False]
[Frame is ignored: False]
[Protocols in frame: eth:ip:udp:data:vssmonitoring]
[Coloring Rule Name: UDP]
[Coloring Rule String: udp]
Ethernet II, Src: ae:4e:20:00:01:00 (ae:4e:20:00:01:00), Dst: Xerox_00:00:00 (01:00:01:00:00:00)
Destination: Xerox_00:00:00 (01:00:01:00:00:00)
Address: Xerox_00:00:00 (01:00:01:00:00:00)
.... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
.... ...1 .... .... .... .... = IG bit: Group address (multicast/broadcast)
Source: ae:4e:20:00:01:00 (ae:4e:20:00:01:00)
Address: ae:4e:20:00:01:00 (ae:4e:20:00:01:00)
.... ..1. .... .... .... .... = LG bit: Locally administered address (this is NOT the factory default)
.... ...0 .... .... .... .... = IG bit: Individual address (unicast)
Type: IP (0x0800)
Internet Protocol Version 4, Src: 192.168.1.50 (192.168.1.50), Dst: 192.168.1.255 (192.168.1.255)
Version: 4
Header length: 20 bytes
Differentiated Services Field: 0x00 (DSCP 0x00: Default; ECN: 0x00: Not-ECT (Not ECN-Capable Transport))
0000 00.. = Differentiated Services Codepoint: Default (0x00)
.... ..00 = Explicit Congestion Notification: Not-ECT (Not ECN-Capable Transport) (0x00)
Total Length: 34
Identification: 0x0032 (50)
Flags: 0x00
0... .... = Reserved bit: Not set
.0.. .... = Don't fragment: Not set
..0. .... = More fragments: Not set
Fragment offset: 0
Time to live: 126
Protocol: UDP (17)
Header checksum: 0xb817 [correct]
[Good: True]
[Bad: False]
Source: 192.168.1.50 (192.168.1.50)
Destination: 192.168.1.255 (192.168.1.255)
[Source GeoIP: Unknown]
[Destination GeoIP: Unknown]
User Datagram Protocol, Src Port: x11 (6001), Dst Port: x11 (6001)
Source port: x11 (6001)
Destination port: x11 (6001)
Length: 14
Checksum: 0xafd1 [validation disabled]
[Good Checksum: False]
[Bad Checksum: False]
Data (6 bytes)
0000 34 34 34 34 34 34 444444
Data: 343434343434
[Length: 6]
VSS-Monitoring ethernet trailer, Source Port: 127
Src Port: 127
我没什么主意了，如果有人能帮忙，请提供任何想法。我不确定这个功能在 win7 中是否被删除。