UDP Payload in fragmented IP packet

[dotpcap]

UDP Payload in fragmented IP packet

[yhw720]

I'm also thinking about the same problem. In case of tcp, fragmented packets area also displayed. I want to know the solution.

[juyanith]

As I mentioned in the edit, you can find the fragment information by using IPv4Packet (or IPv6Packet I assume) instead of just IpPacket. Then you can test for fragmentation and rebuild everything. For example:

    // Is this packet framented?
    if (ipPacket.FragmentOffset > 0 || (ipPacket.FragmentFlags & 0x01) == 0x01)
    {
        // manage fragments 
    }

The issue with my original code is that the packets after the first one do not have a UDP header so the second call to Extract fails. What I ended up doing was writing a fragment manager class to keep track of them. When I added then last fragment it would return the complete set so I could reassemble the entire byte array and process the data.