How to disable loopback packets in NDIS protocol driver

How do I disable receiving loopback packets in protocol driver? The scenario is, my protocol driver is receiving packets from one adapter and sending it over to another. (like eth0 -> eth1).

Interested only in IPv4,

#define NPROT_ETH_TYPE               0x0008 //IPv4

The filter is defined as,

                                NDIS_PACKET_TYPE_DIRECTED/*|    \
                                NDIS_PACKET_TYPE_MULTICAST|   \

The receiving side is checking for loopback packets as shown below,

    // Leave the packet if loopback flag is set.
    if( NdisTestNblFlag( pNetBufList, NDIS_NBL_FLAGS_IS_LOOPBACK_PACKET ))
        // Ndisprot is not interested in this NetBufferList, return the
        // NetBufferList back to the miniport if the miniport gave us
        // ownership of it.

and when I send packets down the road, the SendFlags is set to zero to avoid loopback as per MSDN.


Even after raising all these hurdles, my prottest is receiving loopback packets, as it is evident from wireshark.

Any idea?

Using NDIS6.0, ndisprot60, Dev: Win7, Test VM: Win2008 R2


If you're setting NDIS_PACKET_TYPE_NO_LOCAL and sending the NBLs without the NDIS_SEND_FLAGS_CHECK_FOR_LOOPBACK flag, then NDIS won't deliver loopback packets to you.

Wireshark isn't showing you what your protocol receives. Each protocol can receive a custom set of traffic. So Wireshark is only showing you what Wireshark receives :)

Need Your Help

Passing a nested datastructure to an applet from JavaScript

javascript arrays associative-array applet

In my page I have an applet. I'd like to pass a some data to an applet function. I've found out how to do this and it worked fine for simple datatypes like strings but I'm having hard time with some

About UNIX Resources Network

Original, collect and organize Developers related documents, information and materials, contains jQuery, Html, CSS, MySQL, .NET, ASP.NET, SQL, objective-c, iPhone, Ruby on Rails, C, SQL Server, Ruby, Arrays, Regex, ASP.NET MVC, WPF, XML, Ajax, DataBase, and so on.